Knowledge

Binary quadratic form

Source 📝

36: 8071:. Lagrange was the first to realize that "a coherent general theory required the simulatenous consideration of all forms." He was the first to recognize the importance of the discriminant and to define the essential notions of equivalence and reduction, which, according to Weil, have "dominated the whole subject of quadratic forms ever since". Lagrange showed that there are finitely many equivalence classes of given discriminant, thereby defining for the first time an arithmetic 6392:"Composition" also sometimes refers to, roughly, a binary operation on binary quadratic forms. The word "roughly" indicates two caveats: only certain pairs of binary quadratic forms can be composed, and the resulting form is not well-defined (although its equivalence class is). The composition operation on equivalence classes is defined by first defining composition of forms and then showing that this induces a well-defined operation on classes. 7054: 8100:. Gauss introduced a very general version of a composition operator that allows composing even forms of different discriminants and imprimitive forms. He replaced Lagrange's equivalence with the more precise notion of proper equivalence, and this enabled him to show that the primitive classes of given discriminant form a 4248: 5509: 7996:
of forms. Each genus is the union of a finite number of equivalence classes of the same discriminant, with the number of classes depending only on the discriminant. In the context of binary quadratic forms, genera can be defined either through congruence classes of numbers represented by forms or by
8017:
There is circumstantial evidence of protohistoric knowledge of algebraic identities involving binary quadratic forms. The first problem concerning binary quadratic forms asks for the existence or construction of representations of integers by particular binary quadratic forms. The prime examples
6826: 8171:
Even so, work on binary quadratic forms with integer coefficients continues to the present. This includes numerous results about quadratic number fields, which can often be translated into the language of binary quadratic forms, but also includes developments about forms themselves or that
6410:
A variety of definitions of composition of forms has been given, often in an attempt to simplify the extremely technical and general definition of Gauss. We present here Arndt's method, because it remains rather general while being simple enough to be amenable to computations by hand. An
1077: 6395:"Composition" can also refer to a binary operation on representations of integers by forms. This operation is substantially more complicated than composition of forms, but arose first historically. We will consider such operations in a separate section below. 4062: 5372: 8124:
These investigations of Gauss strongly influenced both the arithmetical theory of quadratic forms in more than two variables and the subsequent development of algebraic number theory, where quadratic fields are replaced with more general
7273:
to be the smallest positive solution to the system of congruences above. Alternatively, we may view the result of composition, not as a form, but as an equivalence class of forms modulo the action of the group of matrices of the form
2766: 5281: 2046: 1574: 5557:
on the set of representations of integers by binary quadratic forms. It follows that equivalence defined this way is an equivalence relation and in particular that the forms in equivalent representations are equivalent forms.
7049:{\displaystyle {\begin{aligned}x&\equiv B_{1}{\pmod {2{\tfrac {A_{1}}{e}}}}\\x&\equiv B_{2}{\pmod {2{\tfrac {A_{2}}{e}}}}\\{\tfrac {B_{\mu }}{e}}x&\equiv {\tfrac {\Delta +B_{1}B_{2}}{2e}}{\pmod {2A}}\end{aligned}}} 687:
Binary quadratic forms are closely related to ideals in quadratic fields. This allows the class number of a quadratic field to be calculated by counting the number of reduced binary quadratic forms of a given discriminant.
1657: 6212:, which ever since has been the reduction algorithm most commonly given in textbooks. In 1981, Zagier published an alternative reduction algorithm which has found several uses as an alternative to Gauss's. 5725: 2242: 773: 7328: 8104:
under the composition operation. He introduced genus theory, which gives a powerful way to understand the quotient of the class group by the subgroup of squares. (Gauss and many subsequent authors wrote
3917: 958: 5364: 2180: 950: 887: 4336:. "Describe" can mean various things: give an algorithm to generate all representations, a closed formula for the number of representations, or even just determine whether any representations exist. 7746: 1382: 627: 6831: 6600: 6508: 4067: 2675: 963: 6688: 1503: 5880: 6323: 5555: 2341: 2092: 1704: 6817: 4765: 2839: 1979: 6756: 188: 8133:
contains truly revolutionary ideas and involves very complicated computations, sometimes left to the reader. Combined, the novelty and complexity made Section V notoriously difficult.
3973: 3659: 333: 4941: 1771: 1141: 7982: 7924: 7866: 7808: 7394: 7201: 7135: 1823: 1440: 7696: 5787: 5663: 5225: 5170: 4879:
The minimum absolute value represented by a class is zero for degenerate classes and positive for definite and indefinite classes. All numbers represented by a definite form
4243:{\displaystyle {\begin{aligned}(3\cdot 17+4\cdot 12,2\cdot 17+3\cdot 12)&=(99,70),\\(3\cdot 99+4\cdot 70,2\cdot 99+3\cdot 70)&=(577,408),\\&\vdots \end{aligned}}} 5929: 5608: 4054: 3740: 3549: 2294: 682: 529: 480: 431: 382: 8139: 5504:{\displaystyle {\begin{pmatrix}\delta &-\beta \\-\gamma &\alpha \end{pmatrix}}{\begin{pmatrix}x_{1}\\y_{1}\end{pmatrix}}={\begin{pmatrix}x_{2}\\y_{2}\end{pmatrix}}} 3796: 3341: 3272: 2994: 2636: 291: 8067: 6044: 5994: 5103: 4503: 4420: 4294: 1892: 8452: 5060: 4666: 4583: 4543: 4460: 4377: 3607: 3485: 3381: 3125: 3030: 8096: 5996:, every representation is equivalent to a unique representation by a reduced form, so a complete set of representatives is given by the finitely many representations of 1251: 1170: 2503: 1222: 6109: 4852: 4804: 4622: 1196: 7637: 6620: 6387: 6363: 6343: 6277: 6253: 6165: 6068: 6018: 5960: 1916: 1862: 6139: 4993: 4967: 3065: 2396: 808: 7617: 7590: 7563: 7536: 7509: 7482: 7455: 7428: 7255: 7228: 4005: 3828: 3691: 3157: 3226: 2662: 3461: 3431: 2945: 7079: 4330: 3401: 3295: 3197: 3177: 3085: 2919: 2899: 2879: 2859: 2590: 2570: 2550: 2459: 2439: 2419: 2670: 232:
This article is entirely devoted to integral binary quadratic forms. This choice is motivated by their status as the driving force behind the development of
8087:, which summarized the work of Euler and Lagrange and added some of his own contributions, including the first glimpse of a composition operation on forms. 6398:
Composition means taking 2 quadratic forms of the same discriminant and combining them to create a quadratic form of the same discriminant, as follows from
5233: 1998: 1526: 1505:. Since Gauss it has been recognized that this definition is inferior to that given above. If there is a need to distinguish, sometimes forms are called 8156: 4545:
at all. In the first case, the sixteen representations were explicitly described. It was also shown that the number of representations of an integer by
8075:. His introduction of reduction allowed the quick enumeration of the classes of given discriminant and foreshadowed the eventual development of 6259:
have since become one of the central ideas in algebraic number theory. From a modern perspective, the class group of a fundamental discriminant
6227:
on primitive equivalence classes of forms of the same discriminant, one of the deepest discoveries of Gauss, which makes this set into a finite
8058:
provided the first proofs of Fermat's observations and added some new conjectures about representations by specific forms, without proof.
4872:
The minimum absolute value represented by a class. This is the smallest nonnegative value in the set of integers represented by a class.
1582: 8206: 8051: 5671: 2188: 1072:{\displaystyle {\begin{aligned}f(\alpha x+\beta y,\gamma x+\delta y)&=g(x,y),\\\alpha \delta -\beta \gamma &=1.\end{aligned}}} 694: 7280: 8005:
in n variables. This states that forms are in the same genus if they are locally equivalent at all rational primes (including the
3836: 5289: 2105: 912: 8137:
published simplifications of the theory that made it accessible to a broader audience. The culmination of this work is his text
6167:. The set of all such representations constitutes a complete set of representatives for equivalence classes of representations. 813: 8026:
in the 7th century CE. Several centuries later, his ideas were extended to a complete solution of Pell's equation known as the
8022:
and the representation of integers as sums of two squares. Pell's equation was already considered by the Indian mathematician
629:
and so on are quadratic forms, and the theory of quadratic forms gives a unified way of looking at and proving these theorems.
7701: 1260: 8557: 8512: 8475: 1706:
on the set of binary quadratic forms. The equivalence relation above then arises from the general theory of group actions.
534: 236:. Since the late nineteenth century, binary quadratic forms have given up their preeminence in algebraic number theory to 6513: 6421: 6629: 1467: 1461:
can mean either a function defined on equivalence classes of forms or a property shared by all forms in the same class.
5792: 8400: 6293: 5517: 2303: 2054: 1666: 79: 57: 6761: 4678: 3559:
in a solution gives another solution, so it is enough to seek just solutions in positive integers. One solution is
2774: 1844:
Terminology has arisen for classifying classes and their forms in terms of their invariants. A form of discriminant
50: 7698:, i.e., with first coefficient 1. (It can be shown that all such forms lie in a single class, and the restriction 1933: 6693: 8050:
made several observations about representations by specific quadratic forms including that which is now known as
7396:
under this action, the middle coefficients of the forms in the class form a congruence class of integers modulo 2
110: 8076: 8629: 8459: 4253:
These values will keep growing in size, so we see there are infinitely many ways to represent 1 by the form
3926: 8619: 5963: 3612: 296: 8624: 7400:. Thus, composition gives a well-defined function from pairs of binary quadratic forms to such classes. 6208: 5882:. This is the recursion step in the process described above for generating infinitely many solutions to 4882: 1712: 5665:. Such a representation is a solution to the Pell equation described in the examples above. The matrix 1085: 8504: 7929: 7871: 7813: 7755: 7341: 7148: 7095: 1783: 1660: 1387: 8006: 7646: 7619:. It follows that composition induces a well-defined operation on primitive classes of discriminant 7265:. One way to make this a well-defined operation is to make an arbitrary convention for how to choose 5737: 5613: 5175: 5120: 8216: 8002: 6399: 5885: 5564: 4010: 3696: 3505: 2250: 638: 485: 436: 387: 338: 8645: 8038:. The problem of representing integers by sums of two squares was considered in the 3rd century by 8031: 3745: 3300: 3231: 2953: 2595: 1927: 250: 44: 6023: 5973: 5065: 4465: 4382: 4256: 1871: 8417: 8165: 8161: 5025: 4631: 4586: 4548: 4508: 4425: 4342: 3562: 3466: 3346: 3090: 3002: 233: 7257:. We see that its first coefficient is well-defined, but the other two depend on the choice of 1227: 1146: 2464: 1201: 101: 61: 6073: 4821: 4773: 4591: 1926:
if its content is 1, that is, if its coefficients are coprime. If a form's discriminant is a
1464:
Lagrange used a different notion of equivalence, in which the second condition is replaced by
1175: 8080: 8023: 7622: 6605: 6372: 6348: 6328: 6262: 6238: 6144: 6053: 6003: 5945: 1901: 1847: 6118: 4972: 4946: 3035: 2366: 778: 8567: 8522: 8485: 8091: 7595: 7568: 7541: 7514: 7487: 7460: 7433: 7406: 7233: 7206: 4339:
The examples above discuss the representation problem for the numbers 3 and 65 by the form
4297: 3978: 3801: 3664: 3130: 1517: 1446: 8612: 8575: 8492: 5931:. Iterating this matrix action, we find that the infinite set of representations of 1 by 4869:
is represented by a form in a class, then it is represented by all other forms in a class.
3202: 2641: 8: 8545: 8118: 8101: 3436: 3406: 2924: 7061: 2761:{\displaystyle {\begin{aligned}65&=1^{2}+8^{2},\\65&=4^{2}+7^{2},\end{aligned}}} 8181: 8019: 7992:
Gauss also considered a coarser notion of equivalence, with each coarse class called a
7639:, and as mentioned above, Gauss showed these classes form a finite abelian group. The 6284: 5938:
There are generally finitely many equivalence classes of representations of an integer
4815: 4315: 3491: 3386: 3280: 3182: 3162: 3070: 2904: 2884: 2864: 2844: 2575: 2555: 2535: 2444: 2424: 2404: 1450: 633: 213:, most results are not specific to the case of two variables, so they are described in 8553: 8541: 8508: 8471: 8396: 8072: 8027: 6366: 5276:{\displaystyle {\begin{pmatrix}\alpha &\beta \\\gamma &\delta \end{pmatrix}}} 2041:{\displaystyle {\begin{pmatrix}\alpha &\beta \\\gamma &\delta \end{pmatrix}}} 1569:{\displaystyle {\begin{pmatrix}\alpha &\beta \\\gamma &\delta \end{pmatrix}}} 8599:
Zetafunktionen und quadratische Körper: eine Einführung in die höhere Zahlentheorie
8571: 8496: 7640: 6224: 6179:, there are only finitely many classes of binary quadratic forms with discriminant 4875:
The congruence classes modulo the discriminant of a class represented by the class.
8563: 8518: 8481: 8467: 8211: 8185: 7749: 6288: 3228:
or 1. We can check these nine pairs directly to see that none of them satisfies
1449:
on the set of integral quadratic forms. It follows that the quadratic forms are
237: 2921:. In all, there are sixteen different solution pairs. On the other hand, when 4296:. This recursive description was discussed in Theon of Smyrna's commentary on 214: 210: 24: 8035: 2841:
that do the trick. We obtain more pairs that work by switching the values of
8639: 8201: 8189: 8173: 7058:
It can be shown that this system always has a unique integer solution modulo
6412: 6228: 8582: 8549: 8533: 8126: 4861:
There are several class invariants relevant to the representation problem:
2352: 1778: 244:, but advances specific to binary quadratic forms still occur on occasion. 241: 8001:
defined on the set of forms. A third definition is a special case of the
8529: 8148: 8043: 6256: 93: 8594: 8177: 8160:, the theory of binary quadratic forms lost its preeminent position in 8039: 6280: 3487:. There are only a finite number of pairs satisfying this constraint. 2529: 8613:
Peter Luschny, Positive numbers represented by a binary quadratic form
23:
coefficients. For binary quadratic forms with other coefficients, see
8587:
Number Theory: An approach through history from Hammurapi to Legendre
8134: 8144: 8062: 3490:
Another ancient problem involving quadratic forms asks us to solve
2297: 1652:{\displaystyle f(x,y)\mapsto f(\alpha x+\beta y,\gamma x+\delta y)} 8466:, Graduate Texts in Mathematics, vol. 138, Berlin, New York: 7748:
implies that there exists such a form of every discriminant.) To
4308:
The oldest problem in the theory of binary quadratic forms is the
8152: 6199:, for constructing a canonical representative in each class, the 5022:
is indefinite. We saw instances of this in the examples above:
4807: 247:
Pierre Fermat stated that if p is an odd prime then the equation
218: 20: 6046:, Zagier proved that every representation of a positive integer 5720:{\displaystyle {\begin{pmatrix}3&-4\\-2&3\end{pmatrix}}} 2237:{\displaystyle {\begin{pmatrix}3&-4\\-2&3\end{pmatrix}}} 768:{\displaystyle \sum _{(m,n)\in \mathbb {Z} ^{2}}q^{m^{2}+n^{2}}} 8047: 8143:. The third edition of this work includes two supplements by 7323:{\displaystyle {\begin{pmatrix}1&n\\0&1\end{pmatrix}}} 8151:, and from then on, especially after the 1897 publication of 8055: 3912:{\displaystyle (3\cdot 3+4\cdot 2,2\cdot 3+3\cdot 2)=(17,12)} 8042:. In the 17th century, inspired while reading Diophantus's 7643:
class in the group is the unique class containing all forms
5359:{\displaystyle f(\alpha x+\beta y,\gamma x+\delta y)=g(x,y)} 2175:{\displaystyle f(\alpha x+\beta y,\gamma x+\delta y)=f(x,y)} 945:{\displaystyle \alpha ,\beta ,\gamma ,{\text{ and }}\delta } 8503:, Cambridge Studies in Advanced Mathematics, vol. 27, 6203:, whose coefficients are the smallest in a suitable sense. 4865:
The set of integers represented by a class. If an integer
2999:
does not have integer solutions. To see why, we note that
882:{\displaystyle \sum _{(m,n)\in \mathbb {Z} ^{2}}q^{f(m,n)}} 8454:, Fermat, class field theory, and complex multiplication 7741:{\displaystyle \Delta \equiv 0{\text{ or }}1{\pmod {4}}} 5514:
The above conditions give a (right) action of the group
1377:{\displaystyle g=(-3x+2y)^{2}+4(-3x+2y)(x-y)+2(x-y)^{2}} 8061:
The general theory of quadratic forms was initiated by
8164:
and became overshadowed by the more general theory of
7289: 6982: 6953: 6926: 6867: 6772: 6647: 5680: 5466: 5423: 5381: 5242: 5113:
The notion of equivalence of forms can be extended to
2197: 2007: 1535: 8420: 7932: 7874: 7816: 7758: 7704: 7649: 7625: 7598: 7571: 7544: 7517: 7490: 7463: 7436: 7409: 7344: 7283: 7236: 7209: 7151: 7098: 7081:. We arbitrarily choose such a solution and call it 7064: 6829: 6764: 6696: 6632: 6608: 6516: 6424: 6375: 6351: 6331: 6296: 6265: 6241: 6147: 6121: 6076: 6056: 6026: 6006: 5976: 5948: 5888: 5795: 5740: 5674: 5616: 5567: 5520: 5375: 5292: 5236: 5178: 5123: 5068: 5028: 4975: 4949: 4885: 4824: 4776: 4681: 4634: 4594: 4551: 4511: 4505:
in infinitely many ways and 3 is not represented by
4468: 4462:
in sixteen different ways, while 1 is represented by
4428: 4385: 4345: 4318: 4259: 4065: 4013: 3981: 3929: 3839: 3804: 3748: 3699: 3667: 3615: 3565: 3508: 3469: 3439: 3409: 3389: 3349: 3303: 3283: 3234: 3205: 3185: 3165: 3133: 3093: 3073: 3038: 3005: 2956: 2927: 2907: 2887: 2867: 2847: 2777: 2673: 2644: 2598: 2578: 2558: 2538: 2467: 2447: 2427: 2407: 2369: 2306: 2253: 2191: 2108: 2057: 2001: 1936: 1904: 1874: 1850: 1828:
The content, equal to the greatest common divisor of
1786: 1715: 1669: 1585: 1529: 1470: 1390: 1263: 1230: 1204: 1178: 1149: 1088: 961: 915: 816: 781: 697: 641: 622:{\displaystyle x^{2}+y^{2},x^{2}+2y^{2},x^{2}-3y^{2}} 537: 488: 439: 390: 341: 299: 253: 113: 8113:; the modern convention allowing the coefficient of 8030:, attributed to either of the Indian mathematicians 5789:
by this matrix yields the equivalent representation
1930:, then the form is primitive. Discriminants satisfy 1520:
terminology, which is used occasionally below, when
335:, and he made similar statement about the equations 8129:. But the impact was not immediate. Section V of 7987: 6595:{\displaystyle f_{2}=A_{2}x^{2}+B_{2}xy+C_{2}y^{2}} 6503:{\displaystyle f_{1}=A_{1}x^{2}+B_{1}xy+C_{1}y^{2}} 3798:is another such pair. For instance, from the pair 3274:, so the equation does not have integer solutions. 8446: 7976: 7918: 7860: 7802: 7740: 7690: 7631: 7611: 7584: 7557: 7530: 7503: 7476: 7449: 7422: 7388: 7322: 7249: 7222: 7195: 7129: 7073: 7048: 6811: 6750: 6683:{\displaystyle B_{\mu }={\tfrac {B_{1}+B_{2}}{2}}} 6682: 6614: 6594: 6502: 6381: 6357: 6337: 6317: 6271: 6247: 6159: 6133: 6103: 6062: 6038: 6012: 5988: 5954: 5923: 5874: 5781: 5719: 5657: 5602: 5549: 5503: 5358: 5275: 5219: 5164: 5097: 5054: 4987: 4961: 4935: 4846: 4798: 4759: 4660: 4616: 4577: 4537: 4497: 4454: 4414: 4371: 4324: 4288: 4242: 4048: 3999: 3967: 3911: 3822: 3790: 3734: 3685: 3653: 3601: 3543: 3479: 3455: 3425: 3395: 3375: 3335: 3289: 3266: 3220: 3191: 3171: 3151: 3119: 3079: 3059: 3024: 2988: 2939: 2913: 2893: 2873: 2853: 2833: 2760: 2656: 2630: 2584: 2564: 2544: 2497: 2453: 2433: 2413: 2390: 2335: 2288: 2236: 2174: 2086: 2040: 1973: 1910: 1886: 1856: 1817: 1765: 1698: 1651: 1568: 1498:{\displaystyle \alpha \delta -\beta \gamma =\pm 1} 1497: 1434: 1376: 1245: 1216: 1190: 1164: 1135: 1071: 944: 881: 802: 767: 676: 621: 523: 474: 425: 376: 327: 285: 182: 19:This article is about binary quadratic forms with 8464:A Course in Computational Algebraic Number Theory 4312:: describe the representations of a given number 3975:. Iterating this process, we find further pairs 3343:can have only a finite number of solutions since 16:Quadratic homogeneous polynomial in two variables 8637: 6703: 5875:{\displaystyle 1=f(3x_{1}+4y_{1},2x_{1}+3y_{1})} 6318:{\displaystyle \mathbf {Q} ({\sqrt {\Delta }})} 5935:that were determined above are all equivalent. 5550:{\displaystyle \mathrm {SL} _{2}(\mathbb {Z} )} 5286:with integer entries and determinant 1 so that 2336:{\displaystyle \mathrm {SL} _{2}(\mathbb {Z} )} 2087:{\displaystyle \mathrm {SL} _{2}(\mathbb {Z} )} 1699:{\displaystyle \mathrm {SL} _{2}(\mathbb {Z} )} 1579:has integer entries and determinant 1, the map 691:The classical theta function of 2 variables is 8617: 8491: 8292: 8172:originated by thinking about forms, including 8090:The theory was vastly extended and refined by 6812:{\displaystyle A={\tfrac {A_{1}A_{2}}{e^{2}}}} 6602:, each primitive and of the same discriminant 6405: 6170: 4760:{\displaystyle r_{2}(n)=4(d_{1}(n)-d_{3}(n)),} 2881:and/or by changing the sign of one or both of 2834:{\displaystyle (x,y)=(1,8){\text{ and }}(4,7)} 6206:Gauss gave a superior reduction algorithm in 5108: 4303: 1974:{\displaystyle \Delta \equiv 0,1{\pmod {4}}.} 7338:is an integer. If we consider the class of 6751:{\displaystyle e=\gcd(A_{1},A_{2},B_{\mu })} 6365:, the narrow class group is the same as the 5730:has determinant 1 and is an automorphism of 5006:The number of representations of an integer 1513:if they are equivalent in Lagrange's sense. 8552:. (6th ed.), Oxford: Clarendon Press, 8528: 8258: 7868:. Alternatively, we can form the class of 5966:for these classes can be given in terms of 2347:is definite, the group is finite, and when 1445:The above equivalence conditions define an 810:is a positive definite quadratic form then 183:{\displaystyle q(x,y)=ax^{2}+bxy+cy^{2},\,} 4995:. For this reason, the former are called 6070:is equivalent to a unique representation 5540: 2326: 2077: 1689: 952:such that the following conditions hold: 842: 723: 209:. When the coefficients can be arbitrary 179: 80:Learn how and when to remove this message 8538:An Introduction to the Theory of Numbers 8188:reinterpretation of composition through 6235:(or simply class group) of discriminant 5227:are equivalent if there exists a matrix 43:This article includes a list of general 8207:Fermat's theorem on sums of two squares 8052:Fermat's theorem on sums of two squares 6411:alternative definition is described at 5942:by forms of given nonzero discriminant 4624:gives the number of representations of 3277:A similar argument shows that for each 2532:considered whether, for an odd integer 632:Another instance of quadratic forms is 8638: 8593: 8281: 8270: 7511:respectively, then the composition of 3968:{\displaystyle 1=17^{2}-2\cdot 12^{2}} 3494:. For instance, we may seek integers 8458: 8234: 6175:Lagrange proved that for every value 3923:and we can check that this satisfies 2296:. The automorphisms of a form are a 8581: 8376: 8364: 8352: 8340: 8328: 8316: 8304: 8246: 7565:is equivalent to the composition of 6195:. He described an algorithm, called 5970:defined in the section below. When 4422:. We see that 65 is represented by 3654:{\displaystyle 1=3^{2}-2\cdot 2^{2}} 1773:, then important invariants include 328:{\displaystyle p\equiv 1{\pmod {4}}} 29: 8391:Johannes Buchmann, Ulrich Vollmer: 7730: 7031: 6921: 6862: 6622:. We perform the following steps: 4936:{\displaystyle f=ax^{2}+bxy+cy^{2}} 2421:if it is possible to find integers 1960: 1766:{\displaystyle f=ax^{2}+bxy+cy^{2}} 317: 13: 7752:a class, we take a representative 7705: 7626: 7099: 6985: 6609: 6376: 6352: 6332: 6307: 6266: 6242: 6057: 6027: 6007: 5977: 5949: 5526: 5523: 4858:that are congruent to 3 modulo 4. 2552:, it is possible to find integers 2351:is indefinite, it is infinite and 2312: 2309: 2063: 2060: 1937: 1905: 1875: 1851: 1787: 1675: 1672: 1136:{\displaystyle f=x^{2}+4xy+2y^{2}} 49:it lacks sufficient corresponding 14: 8657: 8606: 7977:{\displaystyle Ax^{2}-Bxy+Cy^{2}} 7919:{\displaystyle Cx^{2}+Bxy+Ay^{2}} 7861:{\displaystyle Ax^{2}-Bxy+Cy^{2}} 7803:{\displaystyle Ax^{2}+Bxy+Cy^{2}} 7389:{\displaystyle Ax^{2}+Bxy+Cy^{2}} 7196:{\displaystyle Ax^{2}+Bxy+Cy^{2}} 7130:{\displaystyle \Delta =B^{2}-4AC} 6418:Suppose we wish to compose forms 6115:is reduced in Zagier's sense and 6000:by reduced forms of discriminant 4379:and for the number 1 by the form 2358: 1818:{\displaystyle \Delta =b^{2}-4ac} 1453:into equivalence classes, called 1435:{\displaystyle -x^{2}+4xy-2y^{2}} 8085:Essai sur la théorie des nombres 7988:Genera of binary quadratic forms 7691:{\displaystyle x^{2}+Bxy+Cy^{2}} 6821:Solve the system of congruences 6298: 5782:{\displaystyle 1=f(x_{1},y_{1})} 5734:. Acting on the representation 5658:{\displaystyle 1=f(x_{1},y_{1})} 5220:{\displaystyle n=g(x_{2},y_{2})} 5165:{\displaystyle m=f(x_{1},y_{1})} 4943:have the same sign: positive if 3609:, that is, there is an equality 1983: 1509:using the definition above and 34: 8370: 8358: 8346: 8334: 7723: 7024: 6914: 6855: 2247:is an automorphism of the form 1953: 310: 8322: 8310: 8298: 8286: 8275: 8264: 8252: 8240: 8228: 8140:Vorlesungen über Zahlentheorie 7734: 7724: 7038: 7025: 6944: 6915: 6885: 6856: 6745: 6706: 6312: 6302: 6215: 6098: 6086: 5924:{\displaystyle 1=x^{2}-2y^{2}} 5869: 5805: 5776: 5750: 5652: 5626: 5610:and consider a representation 5603:{\displaystyle f=x^{2}-2y^{2}} 5544: 5536: 5353: 5341: 5332: 5296: 5214: 5188: 5159: 5133: 4841: 4835: 4793: 4787: 4751: 4748: 4742: 4726: 4720: 4707: 4698: 4692: 4611: 4605: 4220: 4208: 4198: 4150: 4140: 4128: 4118: 4070: 4049:{\displaystyle 1=x^{2}-2y^{2}} 3994: 3982: 3906: 3894: 3888: 3840: 3817: 3805: 3785: 3749: 3735:{\displaystyle 1=x^{2}-2y^{2}} 3680: 3668: 3596: 3584: 3578: 3566: 3544:{\displaystyle 1=x^{2}-2y^{2}} 3449: 3441: 3419: 3411: 3159:is one of the nine pairs with 3146: 3134: 2828: 2816: 2808: 2796: 2790: 2778: 2489: 2477: 2385: 2373: 2330: 2322: 2289:{\displaystyle f=x^{2}-2y^{2}} 2169: 2157: 2148: 2112: 2081: 2073: 1992:is a quadratic form, a matrix 1964: 1954: 1693: 1685: 1646: 1610: 1604: 1601: 1589: 1365: 1352: 1343: 1331: 1328: 1307: 1292: 1270: 1030: 1018: 1005: 969: 892: 874: 862: 834: 822: 797: 785: 715: 703: 677:{\displaystyle x^{2}-ny^{2}=1} 524:{\displaystyle p=x^{2}-3y^{2}} 475:{\displaystyle p=x^{2}-2y^{2}} 426:{\displaystyle p=x^{2}+3y^{2}} 377:{\displaystyle p=x^{2}+2y^{2}} 321: 311: 223:integral binary quadratic form 129: 117: 1: 8385: 4854:is the number of divisors of 4672:. There is a closed formula 3791:{\displaystyle (3x+4y,2x+3y)} 3336:{\displaystyle n=x^{2}+y^{2}} 3267:{\displaystyle 3=x^{2}+y^{2}} 2989:{\displaystyle 3=x^{2}+y^{2}} 2631:{\displaystyle n=x^{2}+y^{2}} 286:{\displaystyle p=x^{2}+y^{2}} 8147:. Supplement XI introduces 6039:{\displaystyle \Delta >0} 5989:{\displaystyle \Delta <0} 5098:{\displaystyle x^{2}-2y^{2}} 5018:is definite and infinite if 4498:{\displaystyle x^{2}-2y^{2}} 4415:{\displaystyle x^{2}-2y^{2}} 4289:{\displaystyle x^{2}-2y^{2}} 1887:{\displaystyle \Delta <0} 7: 8625:Encyclopedia of Mathematics 8447:{\displaystyle x^{2}+y^{2}} 8195: 8097:Disquisitiones Arithmeticae 6406:Composing forms and classes 6209:Disquisitiones Arithmeticae 6171:Reduction and class numbers 5055:{\displaystyle x^{2}+y^{2}} 4661:{\displaystyle x^{2}+y^{2}} 4578:{\displaystyle x^{2}+y^{2}} 4538:{\displaystyle x^{2}+y^{2}} 4455:{\displaystyle x^{2}+y^{2}} 4372:{\displaystyle x^{2}+y^{2}} 3602:{\displaystyle (x,y)=(3,2)} 3480:{\displaystyle {\sqrt {n}}} 3403:unless the absolute values 3376:{\displaystyle x^{2}+y^{2}} 3120:{\displaystyle x^{2}+y^{2}} 3025:{\displaystyle x^{2}\geq 4} 2524: 2182:. For example, the matrix 10: 8662: 8505:Cambridge University Press 8293:Fröhlich & Taylor 1993 8012: 6223:most commonly refers to a 6050:by a form of discriminant 5115:equivalent representations 5109:Equivalent representations 4332:by a given quadratic form 4304:The representation problem 1246:{\displaystyle \delta =-1} 1165:{\displaystyle \alpha =-3} 221:coefficients is called an 18: 8409:, Springer, New York 1989 8395:, Springer, Berlin 2007, 8068:Recherches d'Arithmétique 8003:genus of a quadratic form 5062:is positive definite and 4999:forms and the latter are 2498:{\displaystyle n=q(x,y).} 1918:is a perfect square, and 1217:{\displaystyle \gamma =1} 217:. A quadratic form with 8618:A. V. Malyshev (2001) , 8222: 7403:It can be shown that if 7203:is "the" composition of 7137:. It can be shown that 6389:it may be twice as big. 6104:{\displaystyle n=f(x,y)} 4847:{\displaystyle d_{3}(n)} 4799:{\displaystyle d_{1}(n)} 4617:{\displaystyle r_{2}(n)} 2461:satisfying the equation 2363:A binary quadratic form 1928:fundamental discriminant 1191:{\displaystyle \beta =2} 909:if there exist integers 8620:"Binary quadratic form" 8501:Algebraic number theory 8259:Hardy & Wright 2008 8166:algebraic number fields 8162:algebraic number theory 7632:{\displaystyle \Delta } 6615:{\displaystyle \Delta } 6382:{\displaystyle \Delta } 6358:{\displaystyle \Delta } 6338:{\displaystyle \Delta } 6272:{\displaystyle \Delta } 6248:{\displaystyle \Delta } 6160:{\displaystyle y\geq 0} 6063:{\displaystyle \Delta } 6013:{\displaystyle \Delta } 5955:{\displaystyle \Delta } 4587:sum of squares function 4585:is always finite. The 1911:{\displaystyle \Delta } 1857:{\displaystyle \Delta } 234:algebraic number theory 225:, often abbreviated to 64:more precise citations. 8448: 8407:Binary Quadratic Forms 8393:Binary Quadratic Forms 8217:Brahmagupta's identity 7978: 7920: 7862: 7810:and form the class of 7804: 7742: 7692: 7633: 7613: 7586: 7559: 7532: 7505: 7478: 7451: 7424: 7390: 7324: 7269:—for instance, choose 7251: 7224: 7197: 7131: 7075: 7057: 7050: 6813: 6752: 6684: 6616: 6596: 6504: 6400:Brahmagupta's identity 6383: 6359: 6339: 6319: 6273: 6249: 6183:. Their number is the 6161: 6135: 6134:{\displaystyle x>0} 6105: 6064: 6040: 6014: 5990: 5956: 5925: 5876: 5783: 5721: 5659: 5604: 5551: 5505: 5360: 5277: 5221: 5166: 5099: 5056: 4989: 4988:{\displaystyle a<0} 4963: 4962:{\displaystyle a>0} 4937: 4848: 4800: 4761: 4662: 4618: 4579: 4539: 4499: 4456: 4416: 4373: 4326: 4310:representation problem 4290: 4244: 4050: 4001: 3969: 3913: 3824: 3792: 3736: 3687: 3655: 3603: 3545: 3481: 3457: 3427: 3397: 3377: 3337: 3291: 3268: 3222: 3193: 3173: 3153: 3121: 3081: 3061: 3060:{\displaystyle x=-1,0} 3026: 2990: 2941: 2915: 2895: 2875: 2855: 2835: 2762: 2658: 2632: 2586: 2566: 2546: 2505:Such an equation is a 2499: 2455: 2435: 2415: 2392: 2391:{\displaystyle q(x,y)} 2337: 2290: 2238: 2176: 2088: 2042: 1975: 1912: 1888: 1858: 1819: 1767: 1700: 1653: 1570: 1499: 1457:of quadratic forms. A 1436: 1384:, which simplifies to 1378: 1247: 1218: 1192: 1166: 1137: 1073: 946: 883: 804: 803:{\displaystyle f(x,y)} 769: 678: 623: 525: 476: 427: 378: 329: 287: 184: 102:homogeneous polynomial 8449: 8180:reduction algorithm, 7979: 7921: 7863: 7805: 7743: 7693: 7634: 7614: 7612:{\displaystyle g_{2}} 7587: 7585:{\displaystyle g_{1}} 7560: 7558:{\displaystyle f_{2}} 7533: 7531:{\displaystyle f_{1}} 7506: 7504:{\displaystyle g_{2}} 7479: 7477:{\displaystyle g_{1}} 7452: 7450:{\displaystyle f_{2}} 7425: 7423:{\displaystyle f_{1}} 7391: 7325: 7252: 7250:{\displaystyle f_{2}} 7225: 7223:{\displaystyle f_{1}} 7198: 7132: 7076: 7051: 6822: 6814: 6753: 6685: 6617: 6597: 6505: 6384: 6360: 6340: 6320: 6274: 6250: 6162: 6136: 6106: 6065: 6041: 6015: 5991: 5962:. A complete set of 5957: 5926: 5877: 5784: 5722: 5660: 5605: 5552: 5506: 5361: 5278: 5222: 5167: 5100: 5057: 4990: 4964: 4938: 4849: 4801: 4762: 4663: 4619: 4580: 4540: 4500: 4457: 4417: 4374: 4327: 4291: 4245: 4051: 4002: 4000:{\displaystyle (x,y)} 3970: 3914: 3825: 3823:{\displaystyle (3,2)} 3793: 3737: 3688: 3686:{\displaystyle (x,y)} 3656: 3604: 3551:. Changing signs of 3546: 3482: 3458: 3428: 3398: 3378: 3338: 3292: 3269: 3223: 3194: 3174: 3154: 3152:{\displaystyle (x,y)} 3127:will exceed 3 unless 3122: 3082: 3062: 3027: 2991: 2942: 2916: 2896: 2876: 2856: 2836: 2763: 2659: 2633: 2587: 2567: 2547: 2500: 2456: 2436: 2416: 2393: 2338: 2291: 2239: 2177: 2089: 2043: 1976: 1922:otherwise. A form is 1913: 1889: 1859: 1820: 1768: 1701: 1654: 1571: 1511:improperly equivalent 1500: 1437: 1379: 1248: 1219: 1193: 1167: 1138: 1074: 947: 889:is a theta function. 884: 805: 770: 679: 624: 526: 477: 428: 379: 330: 288: 227:binary quadratic form 185: 98:binary quadratic form 8418: 8117:to be odd is due to 8018:are the solution of 7930: 7872: 7814: 7756: 7702: 7647: 7623: 7596: 7569: 7542: 7515: 7488: 7461: 7434: 7407: 7342: 7281: 7234: 7207: 7149: 7096: 7062: 6827: 6762: 6694: 6630: 6606: 6514: 6422: 6373: 6349: 6329: 6294: 6263: 6239: 6145: 6119: 6074: 6054: 6024: 6004: 5974: 5946: 5886: 5793: 5738: 5672: 5614: 5565: 5518: 5373: 5290: 5234: 5176: 5121: 5066: 5026: 4973: 4947: 4883: 4822: 4774: 4679: 4632: 4592: 4549: 4509: 4466: 4426: 4383: 4343: 4316: 4257: 4063: 4011: 3979: 3927: 3837: 3802: 3746: 3697: 3665: 3613: 3563: 3506: 3467: 3437: 3407: 3387: 3347: 3301: 3281: 3232: 3221:{\displaystyle -1,0} 3203: 3183: 3163: 3131: 3091: 3071: 3036: 3003: 2954: 2925: 2905: 2885: 2865: 2845: 2775: 2671: 2657:{\displaystyle n=65} 2642: 2596: 2576: 2556: 2536: 2465: 2445: 2425: 2405: 2367: 2304: 2251: 2189: 2106: 2055: 1999: 1934: 1902: 1872: 1848: 1784: 1713: 1667: 1583: 1527: 1468: 1447:equivalence relation 1388: 1261: 1228: 1202: 1176: 1147: 1086: 959: 913: 814: 779: 695: 639: 535: 486: 437: 388: 339: 297: 251: 111: 8589:, Birkhäuser Boston 8414:Primes of the form 6369:, but for positive 5561:As an example, let 5117:. Representations 3693:is any solution to 3463:are both less than 3456:{\displaystyle |y|} 3426:{\displaystyle |x|} 2940:{\displaystyle n=3} 1507:properly equivalent 293:has a solution iff 8493:Fröhlich, Albrecht 8444: 7974: 7916: 7858: 7800: 7738: 7688: 7629: 7609: 7582: 7555: 7528: 7501: 7474: 7457:are equivalent to 7447: 7420: 7386: 7320: 7314: 7247: 7220: 7193: 7127: 7074:{\displaystyle 2A} 7071: 7046: 7044: 7021: 6969: 6942: 6883: 6809: 6807: 6748: 6680: 6678: 6612: 6592: 6500: 6379: 6355: 6335: 6315: 6285:narrow class group 6269: 6245: 6157: 6131: 6101: 6060: 6036: 6010: 5986: 5952: 5921: 5872: 5779: 5717: 5711: 5655: 5600: 5547: 5501: 5495: 5452: 5412: 5356: 5273: 5267: 5217: 5162: 5095: 5052: 4985: 4959: 4933: 4844: 4818:to 1 modulo 4 and 4796: 4757: 4658: 4614: 4575: 4535: 4495: 4452: 4412: 4369: 4322: 4286: 4240: 4238: 4046: 3997: 3965: 3909: 3820: 3788: 3732: 3683: 3651: 3599: 3541: 3477: 3453: 3423: 3393: 3373: 3333: 3287: 3264: 3218: 3189: 3169: 3149: 3117: 3077: 3057: 3022: 2986: 2937: 2911: 2891: 2871: 2851: 2831: 2758: 2756: 2654: 2628: 2582: 2562: 2542: 2495: 2451: 2431: 2411: 2388: 2333: 2286: 2234: 2228: 2172: 2084: 2038: 2032: 1971: 1908: 1884: 1854: 1815: 1763: 1696: 1649: 1566: 1560: 1495: 1432: 1374: 1243: 1214: 1188: 1162: 1133: 1082:For example, with 1069: 1067: 942: 879: 853: 800: 765: 734: 674: 619: 521: 472: 423: 374: 325: 283: 180: 8559:978-0-19-921986-5 8542:D. R. Heath-Brown 8514:978-0-521-43834-6 8477:978-3-540-55640-4 8405:Duncan A. Buell: 8355:, Ch.III §§VII-IX 8343:, Ch.II §§VIII-XI 8307:, Ch.I §§VI, VIII 8028:chakravala method 8007:Archimedean place 7717: 7020: 6968: 6941: 6882: 6806: 6677: 6367:ideal class group 6310: 5001:negative definite 4997:positive definite 4806:is the number of 4668:as a function of 4325:{\displaystyle n} 4298:Euclid's Elements 3475: 3396:{\displaystyle n} 3290:{\displaystyle n} 3192:{\displaystyle y} 3172:{\displaystyle x} 3080:{\displaystyle 1} 2914:{\displaystyle y} 2894:{\displaystyle x} 2874:{\displaystyle y} 2854:{\displaystyle x} 2814: 2771:so we find pairs 2585:{\displaystyle y} 2565:{\displaystyle x} 2545:{\displaystyle n} 2454:{\displaystyle y} 2434:{\displaystyle x} 2414:{\displaystyle n} 1257:is equivalent to 937: 817: 698: 240:and more general 104:in two variables 90: 89: 82: 8653: 8632: 8602: 8590: 8578: 8525: 8488: 8453: 8451: 8450: 8445: 8443: 8442: 8430: 8429: 8380: 8374: 8368: 8362: 8356: 8350: 8344: 8338: 8332: 8326: 8320: 8314: 8308: 8302: 8296: 8290: 8284: 8279: 8273: 8268: 8262: 8256: 8250: 8244: 8238: 8232: 8184:topographs, and 8176:infrastructure, 8094:in Section V of 7999:genus characters 7984:are equivalent. 7983: 7981: 7980: 7975: 7973: 7972: 7945: 7944: 7925: 7923: 7922: 7917: 7915: 7914: 7887: 7886: 7867: 7865: 7864: 7859: 7857: 7856: 7829: 7828: 7809: 7807: 7806: 7801: 7799: 7798: 7771: 7770: 7747: 7745: 7744: 7739: 7737: 7718: 7715: 7697: 7695: 7694: 7689: 7687: 7686: 7659: 7658: 7638: 7636: 7635: 7630: 7618: 7616: 7615: 7610: 7608: 7607: 7591: 7589: 7588: 7583: 7581: 7580: 7564: 7562: 7561: 7556: 7554: 7553: 7537: 7535: 7534: 7529: 7527: 7526: 7510: 7508: 7507: 7502: 7500: 7499: 7483: 7481: 7480: 7475: 7473: 7472: 7456: 7454: 7453: 7448: 7446: 7445: 7429: 7427: 7426: 7421: 7419: 7418: 7395: 7393: 7392: 7387: 7385: 7384: 7357: 7356: 7329: 7327: 7326: 7321: 7319: 7318: 7256: 7254: 7253: 7248: 7246: 7245: 7229: 7227: 7226: 7221: 7219: 7218: 7202: 7200: 7199: 7194: 7192: 7191: 7164: 7163: 7136: 7134: 7133: 7128: 7114: 7113: 7080: 7078: 7077: 7072: 7055: 7053: 7052: 7047: 7045: 7041: 7022: 7019: 7011: 7010: 7009: 7000: 6999: 6983: 6970: 6964: 6963: 6954: 6947: 6943: 6937: 6936: 6927: 6912: 6911: 6888: 6884: 6878: 6877: 6868: 6853: 6852: 6818: 6816: 6815: 6810: 6808: 6805: 6804: 6795: 6794: 6793: 6784: 6783: 6773: 6757: 6755: 6754: 6749: 6744: 6743: 6731: 6730: 6718: 6717: 6689: 6687: 6686: 6681: 6679: 6673: 6672: 6671: 6659: 6658: 6648: 6642: 6641: 6621: 6619: 6618: 6613: 6601: 6599: 6598: 6593: 6591: 6590: 6581: 6580: 6562: 6561: 6549: 6548: 6539: 6538: 6526: 6525: 6509: 6507: 6506: 6501: 6499: 6498: 6489: 6488: 6470: 6469: 6457: 6456: 6447: 6446: 6434: 6433: 6388: 6386: 6385: 6380: 6364: 6362: 6361: 6356: 6344: 6342: 6341: 6336: 6325:of discriminant 6324: 6322: 6321: 6316: 6311: 6306: 6301: 6278: 6276: 6275: 6270: 6254: 6252: 6251: 6246: 6233:form class group 6225:binary operation 6191:of discriminant 6189: 6188: 6166: 6164: 6163: 6158: 6140: 6138: 6137: 6132: 6110: 6108: 6107: 6102: 6069: 6067: 6066: 6061: 6045: 6043: 6042: 6037: 6019: 6017: 6016: 6011: 5995: 5993: 5992: 5987: 5961: 5959: 5958: 5953: 5930: 5928: 5927: 5922: 5920: 5919: 5904: 5903: 5881: 5879: 5878: 5873: 5868: 5867: 5852: 5851: 5836: 5835: 5820: 5819: 5788: 5786: 5785: 5780: 5775: 5774: 5762: 5761: 5726: 5724: 5723: 5718: 5716: 5715: 5664: 5662: 5661: 5656: 5651: 5650: 5638: 5637: 5609: 5607: 5606: 5601: 5599: 5598: 5583: 5582: 5556: 5554: 5553: 5548: 5543: 5535: 5534: 5529: 5510: 5508: 5507: 5502: 5500: 5499: 5492: 5491: 5478: 5477: 5457: 5456: 5449: 5448: 5435: 5434: 5417: 5416: 5365: 5363: 5362: 5357: 5282: 5280: 5279: 5274: 5272: 5271: 5226: 5224: 5223: 5218: 5213: 5212: 5200: 5199: 5171: 5169: 5168: 5163: 5158: 5157: 5145: 5144: 5104: 5102: 5101: 5096: 5094: 5093: 5078: 5077: 5061: 5059: 5058: 5053: 5051: 5050: 5038: 5037: 4994: 4992: 4991: 4986: 4969:and negative if 4968: 4966: 4965: 4960: 4942: 4940: 4939: 4934: 4932: 4931: 4904: 4903: 4853: 4851: 4850: 4845: 4834: 4833: 4805: 4803: 4802: 4797: 4786: 4785: 4766: 4764: 4763: 4758: 4741: 4740: 4719: 4718: 4691: 4690: 4667: 4665: 4664: 4659: 4657: 4656: 4644: 4643: 4623: 4621: 4620: 4615: 4604: 4603: 4584: 4582: 4581: 4576: 4574: 4573: 4561: 4560: 4544: 4542: 4541: 4536: 4534: 4533: 4521: 4520: 4504: 4502: 4501: 4496: 4494: 4493: 4478: 4477: 4461: 4459: 4458: 4453: 4451: 4450: 4438: 4437: 4421: 4419: 4418: 4413: 4411: 4410: 4395: 4394: 4378: 4376: 4375: 4370: 4368: 4367: 4355: 4354: 4331: 4329: 4328: 4323: 4295: 4293: 4292: 4287: 4285: 4284: 4269: 4268: 4249: 4247: 4246: 4241: 4239: 4229: 4055: 4053: 4052: 4047: 4045: 4044: 4029: 4028: 4006: 4004: 4003: 3998: 3974: 3972: 3971: 3966: 3964: 3963: 3945: 3944: 3918: 3916: 3915: 3910: 3829: 3827: 3826: 3821: 3797: 3795: 3794: 3789: 3741: 3739: 3738: 3733: 3731: 3730: 3715: 3714: 3692: 3690: 3689: 3684: 3660: 3658: 3657: 3652: 3650: 3649: 3631: 3630: 3608: 3606: 3605: 3600: 3550: 3548: 3547: 3542: 3540: 3539: 3524: 3523: 3486: 3484: 3483: 3478: 3476: 3471: 3462: 3460: 3459: 3454: 3452: 3444: 3432: 3430: 3429: 3424: 3422: 3414: 3402: 3400: 3399: 3394: 3382: 3380: 3379: 3374: 3372: 3371: 3359: 3358: 3342: 3340: 3339: 3334: 3332: 3331: 3319: 3318: 3296: 3294: 3293: 3288: 3273: 3271: 3270: 3265: 3263: 3262: 3250: 3249: 3227: 3225: 3224: 3219: 3198: 3196: 3195: 3190: 3178: 3176: 3175: 3170: 3158: 3156: 3155: 3150: 3126: 3124: 3123: 3118: 3116: 3115: 3103: 3102: 3086: 3084: 3083: 3078: 3066: 3064: 3063: 3058: 3031: 3029: 3028: 3023: 3015: 3014: 2995: 2993: 2992: 2987: 2985: 2984: 2972: 2971: 2946: 2944: 2943: 2938: 2920: 2918: 2917: 2912: 2900: 2898: 2897: 2892: 2880: 2878: 2877: 2872: 2860: 2858: 2857: 2852: 2840: 2838: 2837: 2832: 2815: 2812: 2767: 2765: 2764: 2759: 2757: 2750: 2749: 2737: 2736: 2710: 2709: 2697: 2696: 2663: 2661: 2660: 2655: 2637: 2635: 2634: 2629: 2627: 2626: 2614: 2613: 2591: 2589: 2588: 2583: 2571: 2569: 2568: 2563: 2551: 2549: 2548: 2543: 2520: 2514: 2504: 2502: 2501: 2496: 2460: 2458: 2457: 2452: 2440: 2438: 2437: 2432: 2420: 2418: 2417: 2412: 2397: 2395: 2394: 2389: 2342: 2340: 2339: 2334: 2329: 2321: 2320: 2315: 2295: 2293: 2292: 2287: 2285: 2284: 2269: 2268: 2243: 2241: 2240: 2235: 2233: 2232: 2181: 2179: 2178: 2173: 2093: 2091: 2090: 2085: 2080: 2072: 2071: 2066: 2047: 2045: 2044: 2039: 2037: 2036: 1980: 1978: 1977: 1972: 1967: 1917: 1915: 1914: 1909: 1893: 1891: 1890: 1885: 1863: 1861: 1860: 1855: 1824: 1822: 1821: 1816: 1802: 1801: 1772: 1770: 1769: 1764: 1762: 1761: 1734: 1733: 1705: 1703: 1702: 1697: 1692: 1684: 1683: 1678: 1658: 1656: 1655: 1650: 1575: 1573: 1572: 1567: 1565: 1564: 1504: 1502: 1501: 1496: 1441: 1439: 1438: 1433: 1431: 1430: 1403: 1402: 1383: 1381: 1380: 1375: 1373: 1372: 1300: 1299: 1253:, we find that 1252: 1250: 1249: 1244: 1223: 1221: 1220: 1215: 1197: 1195: 1194: 1189: 1171: 1169: 1168: 1163: 1142: 1140: 1139: 1134: 1132: 1131: 1104: 1103: 1078: 1076: 1075: 1070: 1068: 951: 949: 948: 943: 938: 935: 888: 886: 885: 880: 878: 877: 852: 851: 850: 845: 809: 807: 806: 801: 774: 772: 771: 766: 764: 763: 762: 761: 749: 748: 733: 732: 731: 726: 683: 681: 680: 675: 667: 666: 651: 650: 628: 626: 625: 620: 618: 617: 602: 601: 589: 588: 573: 572: 560: 559: 547: 546: 530: 528: 527: 522: 520: 519: 504: 503: 481: 479: 478: 473: 471: 470: 455: 454: 432: 430: 429: 424: 422: 421: 406: 405: 383: 381: 380: 375: 373: 372: 357: 356: 334: 332: 331: 326: 324: 292: 290: 289: 284: 282: 281: 269: 268: 189: 187: 186: 181: 175: 174: 147: 146: 85: 78: 74: 71: 65: 60:this article by 51:inline citations 38: 37: 30: 8661: 8660: 8656: 8655: 8654: 8652: 8651: 8650: 8646:Quadratic forms 8636: 8635: 8609: 8560: 8548:. Foreword by 8546:J. H. Silverman 8515: 8478: 8468:Springer-Verlag 8438: 8434: 8425: 8421: 8419: 8416: 8415: 8388: 8383: 8375: 8371: 8363: 8359: 8351: 8347: 8339: 8335: 8327: 8323: 8315: 8311: 8303: 8299: 8291: 8287: 8280: 8276: 8269: 8265: 8257: 8253: 8245: 8241: 8233: 8229: 8225: 8212:Legendre symbol 8198: 8065:in 1775 in his 8020:Pell's equation 8015: 7990: 7968: 7964: 7940: 7936: 7931: 7928: 7927: 7926:since this and 7910: 7906: 7882: 7878: 7873: 7870: 7869: 7852: 7848: 7824: 7820: 7815: 7812: 7811: 7794: 7790: 7766: 7762: 7757: 7754: 7753: 7722: 7714: 7703: 7700: 7699: 7682: 7678: 7654: 7650: 7648: 7645: 7644: 7624: 7621: 7620: 7603: 7599: 7597: 7594: 7593: 7576: 7572: 7570: 7567: 7566: 7549: 7545: 7543: 7540: 7539: 7522: 7518: 7516: 7513: 7512: 7495: 7491: 7489: 7486: 7485: 7468: 7464: 7462: 7459: 7458: 7441: 7437: 7435: 7432: 7431: 7414: 7410: 7408: 7405: 7404: 7380: 7376: 7352: 7348: 7343: 7340: 7339: 7313: 7312: 7307: 7301: 7300: 7295: 7285: 7284: 7282: 7279: 7278: 7241: 7237: 7235: 7232: 7231: 7214: 7210: 7208: 7205: 7204: 7187: 7183: 7159: 7155: 7150: 7147: 7146: 7109: 7105: 7097: 7094: 7093: 7063: 7060: 7059: 7043: 7042: 7023: 7012: 7005: 7001: 6995: 6991: 6984: 6981: 6974: 6959: 6955: 6952: 6949: 6948: 6932: 6928: 6925: 6913: 6907: 6903: 6896: 6890: 6889: 6873: 6869: 6866: 6854: 6848: 6844: 6837: 6830: 6828: 6825: 6824: 6800: 6796: 6789: 6785: 6779: 6775: 6774: 6771: 6763: 6760: 6759: 6739: 6735: 6726: 6722: 6713: 6709: 6695: 6692: 6691: 6667: 6663: 6654: 6650: 6649: 6646: 6637: 6633: 6631: 6628: 6627: 6607: 6604: 6603: 6586: 6582: 6576: 6572: 6557: 6553: 6544: 6540: 6534: 6530: 6521: 6517: 6515: 6512: 6511: 6494: 6490: 6484: 6480: 6465: 6461: 6452: 6448: 6442: 6438: 6429: 6425: 6423: 6420: 6419: 6408: 6374: 6371: 6370: 6350: 6347: 6346: 6345:. For negative 6330: 6327: 6326: 6305: 6297: 6295: 6292: 6291: 6289:quadratic field 6264: 6261: 6260: 6240: 6237: 6236: 6218: 6186: 6185: 6173: 6146: 6143: 6142: 6120: 6117: 6116: 6075: 6072: 6071: 6055: 6052: 6051: 6025: 6022: 6021: 6005: 6002: 6001: 5975: 5972: 5971: 5964:representatives 5947: 5944: 5943: 5915: 5911: 5899: 5895: 5887: 5884: 5883: 5863: 5859: 5847: 5843: 5831: 5827: 5815: 5811: 5794: 5791: 5790: 5770: 5766: 5757: 5753: 5739: 5736: 5735: 5710: 5709: 5704: 5695: 5694: 5686: 5676: 5675: 5673: 5670: 5669: 5646: 5642: 5633: 5629: 5615: 5612: 5611: 5594: 5590: 5578: 5574: 5566: 5563: 5562: 5539: 5530: 5522: 5521: 5519: 5516: 5515: 5494: 5493: 5487: 5483: 5480: 5479: 5473: 5469: 5462: 5461: 5451: 5450: 5444: 5440: 5437: 5436: 5430: 5426: 5419: 5418: 5411: 5410: 5405: 5396: 5395: 5387: 5377: 5376: 5374: 5371: 5370: 5291: 5288: 5287: 5266: 5265: 5260: 5254: 5253: 5248: 5238: 5237: 5235: 5232: 5231: 5208: 5204: 5195: 5191: 5177: 5174: 5173: 5153: 5149: 5140: 5136: 5122: 5119: 5118: 5111: 5105:is indefinite. 5089: 5085: 5073: 5069: 5067: 5064: 5063: 5046: 5042: 5033: 5029: 5027: 5024: 5023: 4974: 4971: 4970: 4948: 4945: 4944: 4927: 4923: 4899: 4895: 4884: 4881: 4880: 4829: 4825: 4823: 4820: 4819: 4781: 4777: 4775: 4772: 4771: 4736: 4732: 4714: 4710: 4686: 4682: 4680: 4677: 4676: 4652: 4648: 4639: 4635: 4633: 4630: 4629: 4599: 4595: 4593: 4590: 4589: 4569: 4565: 4556: 4552: 4550: 4547: 4546: 4529: 4525: 4516: 4512: 4510: 4507: 4506: 4489: 4485: 4473: 4469: 4467: 4464: 4463: 4446: 4442: 4433: 4429: 4427: 4424: 4423: 4406: 4402: 4390: 4386: 4384: 4381: 4380: 4363: 4359: 4350: 4346: 4344: 4341: 4340: 4317: 4314: 4313: 4306: 4280: 4276: 4264: 4260: 4258: 4255: 4254: 4237: 4236: 4227: 4226: 4201: 4147: 4146: 4121: 4066: 4064: 4061: 4060: 4040: 4036: 4024: 4020: 4012: 4009: 4008: 3980: 3977: 3976: 3959: 3955: 3940: 3936: 3928: 3925: 3924: 3838: 3835: 3834: 3803: 3800: 3799: 3747: 3744: 3743: 3726: 3722: 3710: 3706: 3698: 3695: 3694: 3666: 3663: 3662: 3645: 3641: 3626: 3622: 3614: 3611: 3610: 3564: 3561: 3560: 3535: 3531: 3519: 3515: 3507: 3504: 3503: 3492:Pell's equation 3470: 3468: 3465: 3464: 3448: 3440: 3438: 3435: 3434: 3418: 3410: 3408: 3405: 3404: 3388: 3385: 3384: 3367: 3363: 3354: 3350: 3348: 3345: 3344: 3327: 3323: 3314: 3310: 3302: 3299: 3298: 3297:, the equation 3282: 3279: 3278: 3258: 3254: 3245: 3241: 3233: 3230: 3229: 3204: 3201: 3200: 3184: 3181: 3180: 3164: 3161: 3160: 3132: 3129: 3128: 3111: 3107: 3098: 3094: 3092: 3089: 3088: 3072: 3069: 3068: 3037: 3034: 3033: 3010: 3006: 3004: 3001: 3000: 2980: 2976: 2967: 2963: 2955: 2952: 2951: 2947:, the equation 2926: 2923: 2922: 2906: 2903: 2902: 2886: 2883: 2882: 2866: 2863: 2862: 2846: 2843: 2842: 2813: and  2811: 2776: 2773: 2772: 2755: 2754: 2745: 2741: 2732: 2728: 2721: 2715: 2714: 2705: 2701: 2692: 2688: 2681: 2674: 2672: 2669: 2668: 2643: 2640: 2639: 2622: 2618: 2609: 2605: 2597: 2594: 2593: 2577: 2574: 2573: 2557: 2554: 2553: 2537: 2534: 2533: 2527: 2516: 2510: 2466: 2463: 2462: 2446: 2443: 2442: 2426: 2423: 2422: 2406: 2403: 2402: 2368: 2365: 2364: 2361: 2325: 2316: 2308: 2307: 2305: 2302: 2301: 2280: 2276: 2264: 2260: 2252: 2249: 2248: 2227: 2226: 2221: 2212: 2211: 2203: 2193: 2192: 2190: 2187: 2186: 2107: 2104: 2103: 2076: 2067: 2059: 2058: 2056: 2053: 2052: 2031: 2030: 2025: 2019: 2018: 2013: 2003: 2002: 2000: 1997: 1996: 1986: 1952: 1935: 1932: 1931: 1903: 1900: 1899: 1873: 1870: 1869: 1849: 1846: 1845: 1797: 1793: 1785: 1782: 1781: 1757: 1753: 1729: 1725: 1714: 1711: 1710: 1688: 1679: 1671: 1670: 1668: 1665: 1664: 1584: 1581: 1580: 1559: 1558: 1553: 1547: 1546: 1541: 1531: 1530: 1528: 1525: 1524: 1469: 1466: 1465: 1459:class invariant 1426: 1422: 1398: 1394: 1389: 1386: 1385: 1368: 1364: 1295: 1291: 1262: 1259: 1258: 1229: 1226: 1225: 1203: 1200: 1199: 1177: 1174: 1173: 1148: 1145: 1144: 1127: 1123: 1099: 1095: 1087: 1084: 1083: 1066: 1065: 1055: 1037: 1036: 1008: 962: 960: 957: 956: 936: and  934: 914: 911: 910: 895: 858: 854: 846: 841: 840: 821: 815: 812: 811: 780: 777: 776: 757: 753: 744: 740: 739: 735: 727: 722: 721: 702: 696: 693: 692: 662: 658: 646: 642: 640: 637: 636: 634:Pell's equation 613: 609: 597: 593: 584: 580: 568: 564: 555: 551: 542: 538: 536: 533: 532: 515: 511: 499: 495: 487: 484: 483: 466: 462: 450: 446: 438: 435: 434: 417: 413: 401: 397: 389: 386: 385: 368: 364: 352: 348: 340: 337: 336: 309: 298: 295: 294: 277: 273: 264: 260: 252: 249: 248: 211:complex numbers 170: 166: 142: 138: 112: 109: 108: 100:is a quadratic 86: 75: 69: 66: 56:Please help to 55: 39: 35: 28: 17: 12: 11: 5: 8659: 8649: 8648: 8634: 8633: 8615: 8608: 8607:External links 8605: 8604: 8603: 8591: 8579: 8558: 8526: 8513: 8497:Taylor, Martin 8489: 8476: 8456: 8441: 8437: 8433: 8428: 8424: 8410: 8403: 8387: 8384: 8382: 8381: 8369: 8357: 8345: 8333: 8321: 8309: 8297: 8285: 8274: 8263: 8251: 8239: 8226: 8224: 8221: 8220: 8219: 8214: 8209: 8204: 8197: 8194: 8190:Bhargava cubes 8131:Disquisitiones 8077:infrastructure 8014: 8011: 7989: 7986: 7971: 7967: 7963: 7960: 7957: 7954: 7951: 7948: 7943: 7939: 7935: 7913: 7909: 7905: 7902: 7899: 7896: 7893: 7890: 7885: 7881: 7877: 7855: 7851: 7847: 7844: 7841: 7838: 7835: 7832: 7827: 7823: 7819: 7797: 7793: 7789: 7786: 7783: 7780: 7777: 7774: 7769: 7765: 7761: 7736: 7733: 7729: 7726: 7721: 7716: or  7713: 7710: 7707: 7685: 7681: 7677: 7674: 7671: 7668: 7665: 7662: 7657: 7653: 7628: 7606: 7602: 7579: 7575: 7552: 7548: 7525: 7521: 7498: 7494: 7471: 7467: 7444: 7440: 7417: 7413: 7383: 7379: 7375: 7372: 7369: 7366: 7363: 7360: 7355: 7351: 7347: 7332: 7331: 7317: 7311: 7308: 7306: 7303: 7302: 7299: 7296: 7294: 7291: 7290: 7288: 7244: 7240: 7217: 7213: 7190: 7186: 7182: 7179: 7176: 7173: 7170: 7167: 7162: 7158: 7154: 7143: 7142: 7141:is an integer. 7126: 7123: 7120: 7117: 7112: 7108: 7104: 7101: 7086: 7070: 7067: 7040: 7037: 7034: 7030: 7027: 7018: 7015: 7008: 7004: 6998: 6994: 6990: 6987: 6980: 6977: 6975: 6973: 6967: 6962: 6958: 6951: 6950: 6946: 6940: 6935: 6931: 6924: 6920: 6917: 6910: 6906: 6902: 6899: 6897: 6895: 6892: 6891: 6887: 6881: 6876: 6872: 6865: 6861: 6858: 6851: 6847: 6843: 6840: 6838: 6836: 6833: 6832: 6819: 6803: 6799: 6792: 6788: 6782: 6778: 6770: 6767: 6747: 6742: 6738: 6734: 6729: 6725: 6721: 6716: 6712: 6708: 6705: 6702: 6699: 6676: 6670: 6666: 6662: 6657: 6653: 6645: 6640: 6636: 6611: 6589: 6585: 6579: 6575: 6571: 6568: 6565: 6560: 6556: 6552: 6547: 6543: 6537: 6533: 6529: 6524: 6520: 6497: 6493: 6487: 6483: 6479: 6476: 6473: 6468: 6464: 6460: 6455: 6451: 6445: 6441: 6437: 6432: 6428: 6413:Bhargava cubes 6407: 6404: 6378: 6354: 6334: 6314: 6309: 6304: 6300: 6268: 6244: 6217: 6214: 6172: 6169: 6156: 6153: 6150: 6130: 6127: 6124: 6100: 6097: 6094: 6091: 6088: 6085: 6082: 6079: 6059: 6035: 6032: 6029: 6009: 5985: 5982: 5979: 5951: 5918: 5914: 5910: 5907: 5902: 5898: 5894: 5891: 5871: 5866: 5862: 5858: 5855: 5850: 5846: 5842: 5839: 5834: 5830: 5826: 5823: 5818: 5814: 5810: 5807: 5804: 5801: 5798: 5778: 5773: 5769: 5765: 5760: 5756: 5752: 5749: 5746: 5743: 5728: 5727: 5714: 5708: 5705: 5703: 5700: 5697: 5696: 5693: 5690: 5687: 5685: 5682: 5681: 5679: 5654: 5649: 5645: 5641: 5636: 5632: 5628: 5625: 5622: 5619: 5597: 5593: 5589: 5586: 5581: 5577: 5573: 5570: 5546: 5542: 5538: 5533: 5528: 5525: 5512: 5511: 5498: 5490: 5486: 5482: 5481: 5476: 5472: 5468: 5467: 5465: 5460: 5455: 5447: 5443: 5439: 5438: 5433: 5429: 5425: 5424: 5422: 5415: 5409: 5406: 5404: 5401: 5398: 5397: 5394: 5391: 5388: 5386: 5383: 5382: 5380: 5355: 5352: 5349: 5346: 5343: 5340: 5337: 5334: 5331: 5328: 5325: 5322: 5319: 5316: 5313: 5310: 5307: 5304: 5301: 5298: 5295: 5284: 5283: 5270: 5264: 5261: 5259: 5256: 5255: 5252: 5249: 5247: 5244: 5243: 5241: 5216: 5211: 5207: 5203: 5198: 5194: 5190: 5187: 5184: 5181: 5161: 5156: 5152: 5148: 5143: 5139: 5135: 5132: 5129: 5126: 5110: 5107: 5092: 5088: 5084: 5081: 5076: 5072: 5049: 5045: 5041: 5036: 5032: 4984: 4981: 4978: 4958: 4955: 4952: 4930: 4926: 4922: 4919: 4916: 4913: 4910: 4907: 4902: 4898: 4894: 4891: 4888: 4877: 4876: 4873: 4870: 4843: 4840: 4837: 4832: 4828: 4795: 4792: 4789: 4784: 4780: 4768: 4767: 4756: 4753: 4750: 4747: 4744: 4739: 4735: 4731: 4728: 4725: 4722: 4717: 4713: 4709: 4706: 4703: 4700: 4697: 4694: 4689: 4685: 4655: 4651: 4647: 4642: 4638: 4613: 4610: 4607: 4602: 4598: 4572: 4568: 4564: 4559: 4555: 4532: 4528: 4524: 4519: 4515: 4492: 4488: 4484: 4481: 4476: 4472: 4449: 4445: 4441: 4436: 4432: 4409: 4405: 4401: 4398: 4393: 4389: 4366: 4362: 4358: 4353: 4349: 4321: 4305: 4302: 4283: 4279: 4275: 4272: 4267: 4263: 4251: 4250: 4235: 4232: 4230: 4228: 4225: 4222: 4219: 4216: 4213: 4210: 4207: 4204: 4202: 4200: 4197: 4194: 4191: 4188: 4185: 4182: 4179: 4176: 4173: 4170: 4167: 4164: 4161: 4158: 4155: 4152: 4149: 4148: 4145: 4142: 4139: 4136: 4133: 4130: 4127: 4124: 4122: 4120: 4117: 4114: 4111: 4108: 4105: 4102: 4099: 4096: 4093: 4090: 4087: 4084: 4081: 4078: 4075: 4072: 4069: 4068: 4043: 4039: 4035: 4032: 4027: 4023: 4019: 4016: 3996: 3993: 3990: 3987: 3984: 3962: 3958: 3954: 3951: 3948: 3943: 3939: 3935: 3932: 3921: 3920: 3908: 3905: 3902: 3899: 3896: 3893: 3890: 3887: 3884: 3881: 3878: 3875: 3872: 3869: 3866: 3863: 3860: 3857: 3854: 3851: 3848: 3845: 3842: 3819: 3816: 3813: 3810: 3807: 3787: 3784: 3781: 3778: 3775: 3772: 3769: 3766: 3763: 3760: 3757: 3754: 3751: 3729: 3725: 3721: 3718: 3713: 3709: 3705: 3702: 3682: 3679: 3676: 3673: 3670: 3648: 3644: 3640: 3637: 3634: 3629: 3625: 3621: 3618: 3598: 3595: 3592: 3589: 3586: 3583: 3580: 3577: 3574: 3571: 3568: 3538: 3534: 3530: 3527: 3522: 3518: 3514: 3511: 3474: 3451: 3447: 3443: 3421: 3417: 3413: 3392: 3370: 3366: 3362: 3357: 3353: 3330: 3326: 3322: 3317: 3313: 3309: 3306: 3286: 3261: 3257: 3253: 3248: 3244: 3240: 3237: 3217: 3214: 3211: 3208: 3199:each equal to 3188: 3168: 3148: 3145: 3142: 3139: 3136: 3114: 3110: 3106: 3101: 3097: 3076: 3056: 3053: 3050: 3047: 3044: 3041: 3021: 3018: 3013: 3009: 2997: 2996: 2983: 2979: 2975: 2970: 2966: 2962: 2959: 2936: 2933: 2930: 2910: 2890: 2870: 2850: 2830: 2827: 2824: 2821: 2818: 2810: 2807: 2804: 2801: 2798: 2795: 2792: 2789: 2786: 2783: 2780: 2769: 2768: 2753: 2748: 2744: 2740: 2735: 2731: 2727: 2724: 2722: 2720: 2717: 2716: 2713: 2708: 2704: 2700: 2695: 2691: 2687: 2684: 2682: 2680: 2677: 2676: 2653: 2650: 2647: 2625: 2621: 2617: 2612: 2608: 2604: 2601: 2581: 2561: 2541: 2526: 2523: 2507:representation 2494: 2491: 2488: 2485: 2482: 2479: 2476: 2473: 2470: 2450: 2430: 2410: 2387: 2384: 2381: 2378: 2375: 2372: 2360: 2359:Representation 2357: 2332: 2328: 2324: 2319: 2314: 2311: 2283: 2279: 2275: 2272: 2267: 2263: 2259: 2256: 2245: 2244: 2231: 2225: 2222: 2220: 2217: 2214: 2213: 2210: 2207: 2204: 2202: 2199: 2198: 2196: 2171: 2168: 2165: 2162: 2159: 2156: 2153: 2150: 2147: 2144: 2141: 2138: 2135: 2132: 2129: 2126: 2123: 2120: 2117: 2114: 2111: 2083: 2079: 2075: 2070: 2065: 2062: 2049: 2048: 2035: 2029: 2026: 2024: 2021: 2020: 2017: 2014: 2012: 2009: 2008: 2006: 1985: 1982: 1970: 1966: 1963: 1959: 1956: 1951: 1948: 1945: 1942: 1939: 1907: 1883: 1880: 1877: 1853: 1842: 1841: 1826: 1814: 1811: 1808: 1805: 1800: 1796: 1792: 1789: 1760: 1756: 1752: 1749: 1746: 1743: 1740: 1737: 1732: 1728: 1724: 1721: 1718: 1695: 1691: 1687: 1682: 1677: 1674: 1648: 1645: 1642: 1639: 1636: 1633: 1630: 1627: 1624: 1621: 1618: 1615: 1612: 1609: 1606: 1603: 1600: 1597: 1594: 1591: 1588: 1577: 1576: 1563: 1557: 1554: 1552: 1549: 1548: 1545: 1542: 1540: 1537: 1536: 1534: 1494: 1491: 1488: 1485: 1482: 1479: 1476: 1473: 1429: 1425: 1421: 1418: 1415: 1412: 1409: 1406: 1401: 1397: 1393: 1371: 1367: 1363: 1360: 1357: 1354: 1351: 1348: 1345: 1342: 1339: 1336: 1333: 1330: 1327: 1324: 1321: 1318: 1315: 1312: 1309: 1306: 1303: 1298: 1294: 1290: 1287: 1284: 1281: 1278: 1275: 1272: 1269: 1266: 1242: 1239: 1236: 1233: 1213: 1210: 1207: 1187: 1184: 1181: 1161: 1158: 1155: 1152: 1130: 1126: 1122: 1119: 1116: 1113: 1110: 1107: 1102: 1098: 1094: 1091: 1080: 1079: 1064: 1061: 1058: 1056: 1054: 1051: 1048: 1045: 1042: 1039: 1038: 1035: 1032: 1029: 1026: 1023: 1020: 1017: 1014: 1011: 1009: 1007: 1004: 1001: 998: 995: 992: 989: 986: 983: 980: 977: 974: 971: 968: 965: 964: 941: 933: 930: 927: 924: 921: 918: 894: 891: 876: 873: 870: 867: 864: 861: 857: 849: 844: 839: 836: 833: 830: 827: 824: 820: 799: 796: 793: 790: 787: 784: 760: 756: 752: 747: 743: 738: 730: 725: 720: 717: 714: 711: 708: 705: 701: 673: 670: 665: 661: 657: 654: 649: 645: 616: 612: 608: 605: 600: 596: 592: 587: 583: 579: 576: 571: 567: 563: 558: 554: 550: 545: 541: 518: 514: 510: 507: 502: 498: 494: 491: 469: 465: 461: 458: 453: 449: 445: 442: 420: 416: 412: 409: 404: 400: 396: 393: 371: 367: 363: 360: 355: 351: 347: 344: 323: 320: 316: 313: 308: 305: 302: 280: 276: 272: 267: 263: 259: 256: 215:quadratic form 191: 190: 178: 173: 169: 165: 162: 159: 156: 153: 150: 145: 141: 137: 134: 131: 128: 125: 122: 119: 116: 88: 87: 42: 40: 33: 25:quadratic form 15: 9: 6: 4: 3: 2: 8658: 8647: 8644: 8643: 8641: 8631: 8627: 8626: 8621: 8616: 8614: 8611: 8610: 8600: 8596: 8592: 8588: 8584: 8580: 8577: 8573: 8569: 8565: 8561: 8555: 8551: 8547: 8543: 8540:, Revised by 8539: 8535: 8534:Wright, E. M. 8531: 8527: 8524: 8520: 8516: 8510: 8506: 8502: 8498: 8494: 8490: 8487: 8483: 8479: 8473: 8469: 8465: 8461: 8457: 8455: 8439: 8435: 8431: 8426: 8422: 8412:David A Cox, 8411: 8408: 8404: 8402: 8401:3-540-46367-4 8398: 8394: 8390: 8389: 8378: 8373: 8366: 8361: 8354: 8349: 8342: 8337: 8330: 8325: 8318: 8313: 8306: 8301: 8294: 8289: 8283: 8278: 8272: 8267: 8260: 8255: 8248: 8243: 8236: 8231: 8227: 8218: 8215: 8213: 8210: 8208: 8205: 8203: 8202:Bhargava cube 8200: 8199: 8193: 8191: 8187: 8183: 8179: 8175: 8169: 8167: 8163: 8159: 8158: 8154: 8150: 8146: 8142: 8141: 8136: 8132: 8128: 8127:number fields 8122: 8120: 8116: 8112: 8108: 8103: 8099: 8098: 8093: 8088: 8086: 8082: 8078: 8074: 8070: 8069: 8064: 8059: 8057: 8053: 8049: 8045: 8041: 8037: 8033: 8029: 8025: 8021: 8010: 8008: 8004: 8000: 7995: 7985: 7969: 7965: 7961: 7958: 7955: 7952: 7949: 7946: 7941: 7937: 7933: 7911: 7907: 7903: 7900: 7897: 7894: 7891: 7888: 7883: 7879: 7875: 7853: 7849: 7845: 7842: 7839: 7836: 7833: 7830: 7825: 7821: 7817: 7795: 7791: 7787: 7784: 7781: 7778: 7775: 7772: 7767: 7763: 7759: 7751: 7731: 7727: 7719: 7711: 7708: 7683: 7679: 7675: 7672: 7669: 7666: 7663: 7660: 7655: 7651: 7642: 7604: 7600: 7577: 7573: 7550: 7546: 7523: 7519: 7496: 7492: 7469: 7465: 7442: 7438: 7415: 7411: 7401: 7399: 7381: 7377: 7373: 7370: 7367: 7364: 7361: 7358: 7353: 7349: 7345: 7337: 7315: 7309: 7304: 7297: 7292: 7286: 7277: 7276: 7275: 7272: 7268: 7264: 7260: 7242: 7238: 7215: 7211: 7188: 7184: 7180: 7177: 7174: 7171: 7168: 7165: 7160: 7156: 7152: 7140: 7124: 7121: 7118: 7115: 7110: 7106: 7102: 7091: 7087: 7084: 7068: 7065: 7056: 7035: 7032: 7028: 7016: 7013: 7006: 7002: 6996: 6992: 6988: 6978: 6976: 6971: 6965: 6960: 6956: 6938: 6933: 6929: 6922: 6918: 6908: 6904: 6900: 6898: 6893: 6879: 6874: 6870: 6863: 6859: 6849: 6845: 6841: 6839: 6834: 6820: 6801: 6797: 6790: 6786: 6780: 6776: 6768: 6765: 6740: 6736: 6732: 6727: 6723: 6719: 6714: 6710: 6700: 6697: 6674: 6668: 6664: 6660: 6655: 6651: 6643: 6638: 6634: 6625: 6624: 6623: 6587: 6583: 6577: 6573: 6569: 6566: 6563: 6558: 6554: 6550: 6545: 6541: 6535: 6531: 6527: 6522: 6518: 6495: 6491: 6485: 6481: 6477: 6474: 6471: 6466: 6462: 6458: 6453: 6449: 6443: 6439: 6435: 6430: 6426: 6416: 6414: 6403: 6401: 6396: 6393: 6390: 6368: 6290: 6286: 6282: 6258: 6234: 6230: 6229:abelian group 6226: 6222: 6213: 6211: 6210: 6204: 6202: 6198: 6194: 6190: 6182: 6178: 6168: 6154: 6151: 6148: 6128: 6125: 6122: 6114: 6095: 6092: 6089: 6083: 6080: 6077: 6049: 6033: 6030: 5999: 5983: 5980: 5969: 5968:reduced forms 5965: 5941: 5936: 5934: 5916: 5912: 5908: 5905: 5900: 5896: 5892: 5889: 5864: 5860: 5856: 5853: 5848: 5844: 5840: 5837: 5832: 5828: 5824: 5821: 5816: 5812: 5808: 5802: 5799: 5796: 5771: 5767: 5763: 5758: 5754: 5747: 5744: 5741: 5733: 5712: 5706: 5701: 5698: 5691: 5688: 5683: 5677: 5668: 5667: 5666: 5647: 5643: 5639: 5634: 5630: 5623: 5620: 5617: 5595: 5591: 5587: 5584: 5579: 5575: 5571: 5568: 5559: 5531: 5496: 5488: 5484: 5474: 5470: 5463: 5458: 5453: 5445: 5441: 5431: 5427: 5420: 5413: 5407: 5402: 5399: 5392: 5389: 5384: 5378: 5369: 5368: 5367: 5350: 5347: 5344: 5338: 5335: 5329: 5326: 5323: 5320: 5317: 5314: 5311: 5308: 5305: 5302: 5299: 5293: 5268: 5262: 5257: 5250: 5245: 5239: 5230: 5229: 5228: 5209: 5205: 5201: 5196: 5192: 5185: 5182: 5179: 5154: 5150: 5146: 5141: 5137: 5130: 5127: 5124: 5116: 5106: 5090: 5086: 5082: 5079: 5074: 5070: 5047: 5043: 5039: 5034: 5030: 5021: 5017: 5014:is finite if 5013: 5009: 5004: 5002: 4998: 4982: 4979: 4976: 4956: 4953: 4950: 4928: 4924: 4920: 4917: 4914: 4911: 4908: 4905: 4900: 4896: 4892: 4889: 4886: 4874: 4871: 4868: 4864: 4863: 4862: 4859: 4857: 4838: 4830: 4826: 4817: 4813: 4809: 4790: 4782: 4778: 4754: 4745: 4737: 4733: 4729: 4723: 4715: 4711: 4704: 4701: 4695: 4687: 4683: 4675: 4674: 4673: 4671: 4653: 4649: 4645: 4640: 4636: 4627: 4608: 4600: 4596: 4588: 4570: 4566: 4562: 4557: 4553: 4530: 4526: 4522: 4517: 4513: 4490: 4486: 4482: 4479: 4474: 4470: 4447: 4443: 4439: 4434: 4430: 4407: 4403: 4399: 4396: 4391: 4387: 4364: 4360: 4356: 4351: 4347: 4337: 4335: 4319: 4311: 4301: 4299: 4281: 4277: 4273: 4270: 4265: 4261: 4233: 4231: 4223: 4217: 4214: 4211: 4205: 4203: 4195: 4192: 4189: 4186: 4183: 4180: 4177: 4174: 4171: 4168: 4165: 4162: 4159: 4156: 4153: 4143: 4137: 4134: 4131: 4125: 4123: 4115: 4112: 4109: 4106: 4103: 4100: 4097: 4094: 4091: 4088: 4085: 4082: 4079: 4076: 4073: 4059: 4058: 4057: 4041: 4037: 4033: 4030: 4025: 4021: 4017: 4014: 3991: 3988: 3985: 3960: 3956: 3952: 3949: 3946: 3941: 3937: 3933: 3930: 3903: 3900: 3897: 3891: 3885: 3882: 3879: 3876: 3873: 3870: 3867: 3864: 3861: 3858: 3855: 3852: 3849: 3846: 3843: 3833: 3832: 3831: 3830:, we compute 3814: 3811: 3808: 3782: 3779: 3776: 3773: 3770: 3767: 3764: 3761: 3758: 3755: 3752: 3727: 3723: 3719: 3716: 3711: 3707: 3703: 3700: 3677: 3674: 3671: 3646: 3642: 3638: 3635: 3632: 3627: 3623: 3619: 3616: 3593: 3590: 3587: 3581: 3575: 3572: 3569: 3558: 3554: 3536: 3532: 3528: 3525: 3520: 3516: 3512: 3509: 3501: 3497: 3493: 3488: 3472: 3445: 3415: 3390: 3368: 3364: 3360: 3355: 3351: 3328: 3324: 3320: 3315: 3311: 3307: 3304: 3284: 3275: 3259: 3255: 3251: 3246: 3242: 3238: 3235: 3215: 3212: 3209: 3206: 3186: 3166: 3143: 3140: 3137: 3112: 3108: 3104: 3099: 3095: 3074: 3054: 3051: 3048: 3045: 3042: 3039: 3019: 3016: 3011: 3007: 2981: 2977: 2973: 2968: 2964: 2960: 2957: 2950: 2949: 2948: 2934: 2931: 2928: 2908: 2888: 2868: 2848: 2825: 2822: 2819: 2805: 2802: 2799: 2793: 2787: 2784: 2781: 2751: 2746: 2742: 2738: 2733: 2729: 2725: 2723: 2718: 2711: 2706: 2702: 2698: 2693: 2689: 2685: 2683: 2678: 2667: 2666: 2665: 2651: 2648: 2645: 2623: 2619: 2615: 2610: 2606: 2602: 2599: 2579: 2559: 2539: 2531: 2522: 2519: 2513: 2508: 2492: 2486: 2483: 2480: 2474: 2471: 2468: 2448: 2428: 2408: 2400: 2382: 2379: 2376: 2370: 2356: 2354: 2350: 2346: 2317: 2299: 2281: 2277: 2273: 2270: 2265: 2261: 2257: 2254: 2229: 2223: 2218: 2215: 2208: 2205: 2200: 2194: 2185: 2184: 2183: 2166: 2163: 2160: 2154: 2151: 2145: 2142: 2139: 2136: 2133: 2130: 2127: 2124: 2121: 2118: 2115: 2109: 2101: 2097: 2068: 2033: 2027: 2022: 2015: 2010: 2004: 1995: 1994: 1993: 1991: 1984:Automorphisms 1981: 1968: 1961: 1957: 1949: 1946: 1943: 1940: 1929: 1925: 1921: 1897: 1881: 1878: 1867: 1839: 1835: 1831: 1827: 1812: 1809: 1806: 1803: 1798: 1794: 1790: 1780: 1776: 1775: 1774: 1758: 1754: 1750: 1747: 1744: 1741: 1738: 1735: 1730: 1726: 1722: 1719: 1716: 1707: 1680: 1662: 1659:is a (right) 1643: 1640: 1637: 1634: 1631: 1628: 1625: 1622: 1619: 1616: 1613: 1607: 1598: 1595: 1592: 1586: 1561: 1555: 1550: 1543: 1538: 1532: 1523: 1522: 1521: 1519: 1514: 1512: 1508: 1492: 1489: 1486: 1483: 1480: 1477: 1474: 1471: 1462: 1460: 1456: 1452: 1448: 1443: 1427: 1423: 1419: 1416: 1413: 1410: 1407: 1404: 1399: 1395: 1391: 1369: 1361: 1358: 1355: 1349: 1346: 1340: 1337: 1334: 1325: 1322: 1319: 1316: 1313: 1310: 1304: 1301: 1296: 1288: 1285: 1282: 1279: 1276: 1273: 1267: 1264: 1256: 1240: 1237: 1234: 1231: 1211: 1208: 1205: 1185: 1182: 1179: 1159: 1156: 1153: 1150: 1128: 1124: 1120: 1117: 1114: 1111: 1108: 1105: 1100: 1096: 1092: 1089: 1062: 1059: 1057: 1052: 1049: 1046: 1043: 1040: 1033: 1027: 1024: 1021: 1015: 1012: 1010: 1002: 999: 996: 993: 990: 987: 984: 981: 978: 975: 972: 966: 955: 954: 953: 939: 931: 928: 925: 922: 919: 916: 908: 904: 900: 890: 871: 868: 865: 859: 855: 847: 837: 831: 828: 825: 818: 794: 791: 788: 782: 758: 754: 750: 745: 741: 736: 728: 718: 712: 709: 706: 699: 689: 685: 671: 668: 663: 659: 655: 652: 647: 643: 635: 630: 614: 610: 606: 603: 598: 594: 590: 585: 581: 577: 574: 569: 565: 561: 556: 552: 548: 543: 539: 516: 512: 508: 505: 500: 496: 492: 489: 467: 463: 459: 456: 451: 447: 443: 440: 418: 414: 410: 407: 402: 398: 394: 391: 369: 365: 361: 358: 353: 349: 345: 342: 318: 314: 306: 303: 300: 278: 274: 270: 265: 261: 257: 254: 245: 243: 242:number fields 239: 235: 230: 228: 224: 220: 216: 212: 208: 204: 200: 196: 176: 171: 167: 163: 160: 157: 154: 151: 148: 143: 139: 135: 132: 126: 123: 120: 114: 107: 106: 105: 103: 99: 95: 84: 81: 73: 63: 59: 53: 52: 46: 41: 32: 31: 26: 22: 8623: 8598: 8586: 8550:Andrew Wiles 8537: 8530:Hardy, G. H. 8500: 8463: 8460:Cohen, Henri 8413: 8406: 8392: 8372: 8360: 8348: 8336: 8324: 8312: 8300: 8295:, Theorem 58 8288: 8277: 8266: 8254: 8249:, p. 30 8242: 8230: 8170: 8155: 8138: 8130: 8123: 8114: 8110: 8109:in place of 8106: 8095: 8089: 8084: 8073:class number 8066: 8060: 8016: 7998: 7993: 7991: 7402: 7397: 7335: 7333: 7270: 7266: 7262: 7258: 7144: 7138: 7089: 7082: 6823: 6417: 6409: 6397: 6394: 6391: 6257:Class groups 6232: 6220: 6219: 6207: 6205: 6201:reduced form 6200: 6196: 6192: 6187:class number 6184: 6180: 6176: 6174: 6112: 6047: 5997: 5967: 5939: 5937: 5932: 5731: 5729: 5560: 5513: 5285: 5114: 5112: 5019: 5015: 5011: 5007: 5005: 5000: 4996: 4878: 4866: 4860: 4855: 4811: 4769: 4669: 4625: 4338: 4333: 4309: 4307: 4252: 3922: 3556: 3552: 3499: 3495: 3489: 3383:will exceed 3276: 2998: 2770: 2528: 2517: 2511: 2506: 2398: 2362: 2348: 2344: 2246: 2099: 2096:automorphism 2095: 2050: 1989: 1987: 1923: 1919: 1895: 1865: 1843: 1837: 1833: 1829: 1779:discriminant 1708: 1661:group action 1578: 1515: 1510: 1506: 1463: 1458: 1454: 1444: 1254: 1081: 906: 902: 898: 896: 690: 686: 631: 246: 231: 226: 222: 207:coefficients 206: 202: 198: 194: 192: 97: 91: 76: 67: 48: 8595:Zagier, Don 8583:Weil, André 8282:Zagier 1981 8271:Zagier 1981 8157:Zahlbericht 8149:ring theory 8079:. In 1798, 8044:Arithmetica 8036:Bhāskara II 8024:Brahmagupta 6231:called the 6221:Composition 6216:Composition 2401:an integer 1451:partitioned 905:are called 893:Equivalence 94:mathematics 62:introducing 8601:, Springer 8576:1159.11001 8386:References 8331:, Ch.I §IX 8319:, Ch.I §IX 8261:, Thm. 278 8235:Cohen 1993 8186:Bhargava's 8119:Eisenstein 8083:published 8040:Diophantus 7092:such that 6281:isomorphic 5010:by a form 2664:, we have 2592:for which 2530:Diophantus 2399:represents 1920:indefinite 1896:degenerate 907:equivalent 897:Two forms 45:references 8630:EMS Press 8536:(2008) , 8377:Weil 2001 8365:Weil 2001 8353:Weil 2001 8341:Weil 2001 8329:Weil 2001 8317:Weil 2001 8305:Weil 2001 8247:Weil 2001 8153:Hilbert's 8135:Dirichlet 7947:− 7831:− 7709:≡ 7706:Δ 7627:Δ 7145:The form 7116:− 7100:Δ 6986:Δ 6979:≡ 6961:μ 6901:≡ 6842:≡ 6741:μ 6639:μ 6610:Δ 6377:Δ 6353:Δ 6333:Δ 6308:Δ 6267:Δ 6243:Δ 6197:reduction 6152:≥ 6111:in which 6058:Δ 6028:Δ 6008:Δ 5978:Δ 5950:Δ 5906:− 5699:− 5689:− 5585:− 5408:α 5403:γ 5400:− 5393:β 5390:− 5385:δ 5327:δ 5318:γ 5309:β 5300:α 5263:δ 5258:γ 5251:β 5246:α 5080:− 4816:congruent 4814:that are 4730:− 4480:− 4397:− 4271:− 4234:⋮ 4193:⋅ 4181:⋅ 4169:⋅ 4157:⋅ 4113:⋅ 4101:⋅ 4089:⋅ 4077:⋅ 4031:− 3953:⋅ 3947:− 3883:⋅ 3871:⋅ 3859:⋅ 3847:⋅ 3717:− 3639:⋅ 3633:− 3526:− 3207:− 3087:. Thus, 3046:− 3017:≥ 2271:− 2216:− 2206:− 2143:δ 2134:γ 2125:β 2116:α 2028:δ 2023:γ 2016:β 2011:α 1941:≡ 1938:Δ 1924:primitive 1906:Δ 1876:Δ 1852:Δ 1804:− 1788:Δ 1641:δ 1632:γ 1623:β 1614:α 1605:↦ 1556:δ 1551:γ 1544:β 1539:α 1490:± 1484:γ 1481:β 1478:− 1475:δ 1472:α 1417:− 1392:− 1359:− 1338:− 1311:− 1274:− 1238:− 1232:δ 1206:γ 1180:β 1157:− 1151:α 1053:γ 1050:β 1047:− 1044:δ 1041:α 1000:δ 991:γ 982:β 973:α 940:δ 929:γ 923:β 917:α 838:∈ 819:∑ 719:∈ 700:∑ 653:− 604:− 506:− 457:− 304:≡ 238:quadratic 70:July 2009 8640:Category 8597:(1981), 8585:(2001), 8499:(1993), 8462:(1993), 8196:See also 8182:Conway's 8178:Zagier's 8174:Shanks's 8145:Dedekind 8081:Legendre 8063:Lagrange 8032:Jayadeva 7641:identity 7088:Compute 6626:Compute 6020:. When 4808:divisors 3502:so that 2525:Examples 2343:. When 2298:subgroup 1866:definite 205:are the 8568:2445243 8523:1215934 8486:1228206 8379:, p.317 8367:, p.318 8013:History 6287:of the 6283:to the 3742:, then 3032:unless 2638:. When 1455:classes 219:integer 58:improve 21:integer 8574:  8566:  8556:  8521:  8511:  8484:  8474:  8399:  8237:, §5.2 8048:Fermat 7750:invert 7334:where 6758:, and 4770:where 2353:cyclic 2094:is an 1836:, and 1518:matrix 1224:, and 193:where 47:, but 8223:Notes 8102:group 8092:Gauss 8056:Euler 7994:genus 4007:with 3661:. If 775:, if 8554:ISBN 8544:and 8509:ISBN 8472:ISBN 8397:ISBN 7592:and 7538:and 7484:and 7430:and 7261:and 7230:and 6690:and 6510:and 6126:> 6031:> 5981:< 5366:and 5172:and 4980:< 4954:> 3555:and 3498:and 3433:and 3179:and 2901:and 2861:and 2572:and 2441:and 1879:< 1777:The 1143:and 901:and 482:and 96:, a 8572:Zbl 8121:). 8034:or 8009:). 7728:mod 7029:mod 6919:mod 6860:mod 6704:gcd 6279:is 6255:. 4810:of 4628:by 4218:408 4212:577 3067:or 2515:by 2509:of 2300:of 2102:if 2098:of 2051:in 1988:If 1958:mod 1898:if 1868:if 1864:is 1709:If 1663:of 1516:In 315:mod 92:In 8642:: 8628:, 8622:, 8570:, 8564:MR 8562:, 8532:; 8519:MR 8517:, 8507:, 8495:; 8482:MR 8480:, 8470:, 8192:. 8168:. 8115:xy 8054:. 8046:, 6415:. 6402:. 6141:, 5003:. 4300:. 4196:70 4184:99 4172:70 4160:99 4138:70 4132:99 4116:12 4104:17 4092:12 4080:17 4056:: 3957:12 3938:17 3904:12 3898:17 2719:65 2679:65 2652:65 2521:. 2355:. 1894:, 1832:, 1442:. 1198:, 1172:, 1063:1. 684:. 531:. 433:, 384:, 229:. 201:, 197:, 8440:2 8436:y 8432:+ 8427:2 8423:x 8111:b 8107:b 8105:2 7970:2 7966:y 7962:C 7959:+ 7956:y 7953:x 7950:B 7942:2 7938:x 7934:A 7912:2 7908:y 7904:A 7901:+ 7898:y 7895:x 7892:B 7889:+ 7884:2 7880:x 7876:C 7854:2 7850:y 7846:C 7843:+ 7840:y 7837:x 7834:B 7826:2 7822:x 7818:A 7796:2 7792:y 7788:C 7785:+ 7782:y 7779:x 7776:B 7773:+ 7768:2 7764:x 7760:A 7735:) 7732:4 7725:( 7720:1 7712:0 7684:2 7680:y 7676:C 7673:+ 7670:y 7667:x 7664:B 7661:+ 7656:2 7652:x 7605:2 7601:g 7578:1 7574:g 7551:2 7547:f 7524:1 7520:f 7497:2 7493:g 7470:1 7466:g 7443:2 7439:f 7416:1 7412:f 7398:A 7382:2 7378:y 7374:C 7371:+ 7368:y 7365:x 7362:B 7359:+ 7354:2 7350:x 7346:A 7336:n 7330:, 7316:) 7310:1 7305:0 7298:n 7293:1 7287:( 7271:B 7267:B 7263:C 7259:B 7243:2 7239:f 7216:1 7212:f 7189:2 7185:y 7181:C 7178:+ 7175:y 7172:x 7169:B 7166:+ 7161:2 7157:x 7153:A 7139:C 7125:C 7122:A 7119:4 7111:2 7107:B 7103:= 7090:C 7085:. 7083:B 7069:A 7066:2 7039:) 7036:A 7033:2 7026:( 7017:e 7014:2 7007:2 7003:B 6997:1 6993:B 6989:+ 6972:x 6966:e 6957:B 6945:) 6939:e 6934:2 6930:A 6923:2 6916:( 6909:2 6905:B 6894:x 6886:) 6880:e 6875:1 6871:A 6864:2 6857:( 6850:1 6846:B 6835:x 6802:2 6798:e 6791:2 6787:A 6781:1 6777:A 6769:= 6766:A 6746:) 6737:B 6733:, 6728:2 6724:A 6720:, 6715:1 6711:A 6707:( 6701:= 6698:e 6675:2 6669:2 6665:B 6661:+ 6656:1 6652:B 6644:= 6635:B 6588:2 6584:y 6578:2 6574:C 6570:+ 6567:y 6564:x 6559:2 6555:B 6551:+ 6546:2 6542:x 6536:2 6532:A 6528:= 6523:2 6519:f 6496:2 6492:y 6486:1 6482:C 6478:+ 6475:y 6472:x 6467:1 6463:B 6459:+ 6454:2 6450:x 6444:1 6440:A 6436:= 6431:1 6427:f 6313:) 6303:( 6299:Q 6193:D 6181:D 6177:D 6155:0 6149:y 6129:0 6123:x 6113:f 6099:) 6096:y 6093:, 6090:x 6087:( 6084:f 6081:= 6078:n 6048:n 6034:0 5998:n 5984:0 5940:n 5933:f 5917:2 5913:y 5909:2 5901:2 5897:x 5893:= 5890:1 5870:) 5865:1 5861:y 5857:3 5854:+ 5849:1 5845:x 5841:2 5838:, 5833:1 5829:y 5825:4 5822:+ 5817:1 5813:x 5809:3 5806:( 5803:f 5800:= 5797:1 5777:) 5772:1 5768:y 5764:, 5759:1 5755:x 5751:( 5748:f 5745:= 5742:1 5732:f 5713:) 5707:3 5702:2 5692:4 5684:3 5678:( 5653:) 5648:1 5644:y 5640:, 5635:1 5631:x 5627:( 5624:f 5621:= 5618:1 5596:2 5592:y 5588:2 5580:2 5576:x 5572:= 5569:f 5545:) 5541:Z 5537:( 5532:2 5527:L 5524:S 5497:) 5489:2 5485:y 5475:2 5471:x 5464:( 5459:= 5454:) 5446:1 5442:y 5432:1 5428:x 5421:( 5414:) 5379:( 5354:) 5351:y 5348:, 5345:x 5342:( 5339:g 5336:= 5333:) 5330:y 5324:+ 5321:x 5315:, 5312:y 5306:+ 5303:x 5297:( 5294:f 5269:) 5240:( 5215:) 5210:2 5206:y 5202:, 5197:2 5193:x 5189:( 5186:g 5183:= 5180:n 5160:) 5155:1 5151:y 5147:, 5142:1 5138:x 5134:( 5131:f 5128:= 5125:m 5091:2 5087:y 5083:2 5075:2 5071:x 5048:2 5044:y 5040:+ 5035:2 5031:x 5020:f 5016:f 5012:f 5008:n 4983:0 4977:a 4957:0 4951:a 4929:2 4925:y 4921:c 4918:+ 4915:y 4912:x 4909:b 4906:+ 4901:2 4897:x 4893:a 4890:= 4887:f 4867:n 4856:n 4842:) 4839:n 4836:( 4831:3 4827:d 4812:n 4794:) 4791:n 4788:( 4783:1 4779:d 4755:, 4752:) 4749:) 4746:n 4743:( 4738:3 4734:d 4727:) 4724:n 4721:( 4716:1 4712:d 4708:( 4705:4 4702:= 4699:) 4696:n 4693:( 4688:2 4684:r 4670:n 4654:2 4650:y 4646:+ 4641:2 4637:x 4626:n 4612:) 4609:n 4606:( 4601:2 4597:r 4571:2 4567:y 4563:+ 4558:2 4554:x 4531:2 4527:y 4523:+ 4518:2 4514:x 4491:2 4487:y 4483:2 4475:2 4471:x 4448:2 4444:y 4440:+ 4435:2 4431:x 4408:2 4404:y 4400:2 4392:2 4388:x 4365:2 4361:y 4357:+ 4352:2 4348:x 4334:f 4320:n 4282:2 4278:y 4274:2 4266:2 4262:x 4224:, 4221:) 4215:, 4209:( 4206:= 4199:) 4190:3 4187:+ 4178:2 4175:, 4166:4 4163:+ 4154:3 4151:( 4144:, 4141:) 4135:, 4129:( 4126:= 4119:) 4110:3 4107:+ 4098:2 4095:, 4086:4 4083:+ 4074:3 4071:( 4042:2 4038:y 4034:2 4026:2 4022:x 4018:= 4015:1 3995:) 3992:y 3989:, 3986:x 3983:( 3961:2 3950:2 3942:2 3934:= 3931:1 3919:, 3907:) 3901:, 3895:( 3892:= 3889:) 3886:2 3880:3 3877:+ 3874:3 3868:2 3865:, 3862:2 3856:4 3853:+ 3850:3 3844:3 3841:( 3818:) 3815:2 3812:, 3809:3 3806:( 3786:) 3783:y 3780:3 3777:+ 3774:x 3771:2 3768:, 3765:y 3762:4 3759:+ 3756:x 3753:3 3750:( 3728:2 3724:y 3720:2 3712:2 3708:x 3704:= 3701:1 3681:) 3678:y 3675:, 3672:x 3669:( 3647:2 3643:2 3636:2 3628:2 3624:3 3620:= 3617:1 3597:) 3594:2 3591:, 3588:3 3585:( 3582:= 3579:) 3576:y 3573:, 3570:x 3567:( 3557:y 3553:x 3537:2 3533:y 3529:2 3521:2 3517:x 3513:= 3510:1 3500:y 3496:x 3473:n 3450:| 3446:y 3442:| 3420:| 3416:x 3412:| 3391:n 3369:2 3365:y 3361:+ 3356:2 3352:x 3329:2 3325:y 3321:+ 3316:2 3312:x 3308:= 3305:n 3285:n 3260:2 3256:y 3252:+ 3247:2 3243:x 3239:= 3236:3 3216:0 3213:, 3210:1 3187:y 3167:x 3147:) 3144:y 3141:, 3138:x 3135:( 3113:2 3109:y 3105:+ 3100:2 3096:x 3075:1 3055:0 3052:, 3049:1 3043:= 3040:x 3020:4 3012:2 3008:x 2982:2 2978:y 2974:+ 2969:2 2965:x 2961:= 2958:3 2935:3 2932:= 2929:n 2909:y 2889:x 2869:y 2849:x 2829:) 2826:7 2823:, 2820:4 2817:( 2809:) 2806:8 2803:, 2800:1 2797:( 2794:= 2791:) 2788:y 2785:, 2782:x 2779:( 2752:, 2747:2 2743:7 2739:+ 2734:2 2730:4 2726:= 2712:, 2707:2 2703:8 2699:+ 2694:2 2690:1 2686:= 2649:= 2646:n 2624:2 2620:y 2616:+ 2611:2 2607:x 2603:= 2600:n 2580:y 2560:x 2540:n 2518:q 2512:n 2493:. 2490:) 2487:y 2484:, 2481:x 2478:( 2475:q 2472:= 2469:n 2449:y 2429:x 2409:n 2386:) 2383:y 2380:, 2377:x 2374:( 2371:q 2349:f 2345:f 2331:) 2327:Z 2323:( 2318:2 2313:L 2310:S 2282:2 2278:y 2274:2 2266:2 2262:x 2258:= 2255:f 2230:) 2224:3 2219:2 2209:4 2201:3 2195:( 2170:) 2167:y 2164:, 2161:x 2158:( 2155:f 2152:= 2149:) 2146:y 2140:+ 2137:x 2131:, 2128:y 2122:+ 2119:x 2113:( 2110:f 2100:f 2082:) 2078:Z 2074:( 2069:2 2064:L 2061:S 2034:) 2005:( 1990:f 1969:. 1965:) 1962:4 1955:( 1950:1 1947:, 1944:0 1882:0 1840:. 1838:c 1834:b 1830:a 1825:. 1813:c 1810:a 1807:4 1799:2 1795:b 1791:= 1759:2 1755:y 1751:c 1748:+ 1745:y 1742:x 1739:b 1736:+ 1731:2 1727:x 1723:a 1720:= 1717:f 1694:) 1690:Z 1686:( 1681:2 1676:L 1673:S 1647:) 1644:y 1638:+ 1635:x 1629:, 1626:y 1620:+ 1617:x 1611:( 1608:f 1602:) 1599:y 1596:, 1593:x 1590:( 1587:f 1562:) 1533:( 1493:1 1487:= 1428:2 1424:y 1420:2 1414:y 1411:x 1408:4 1405:+ 1400:2 1396:x 1370:2 1366:) 1362:y 1356:x 1353:( 1350:2 1347:+ 1344:) 1341:y 1335:x 1332:( 1329:) 1326:y 1323:2 1320:+ 1317:x 1314:3 1308:( 1305:4 1302:+ 1297:2 1293:) 1289:y 1286:2 1283:+ 1280:x 1277:3 1271:( 1268:= 1265:g 1255:f 1241:1 1235:= 1212:1 1209:= 1186:2 1183:= 1160:3 1154:= 1129:2 1125:y 1121:2 1118:+ 1115:y 1112:x 1109:4 1106:+ 1101:2 1097:x 1093:= 1090:f 1060:= 1034:, 1031:) 1028:y 1025:, 1022:x 1019:( 1016:g 1013:= 1006:) 1003:y 997:+ 994:x 988:, 985:y 979:+ 976:x 970:( 967:f 932:, 926:, 920:, 903:g 899:f 875:) 872:n 869:, 866:m 863:( 860:f 856:q 848:2 843:Z 835:) 832:n 829:, 826:m 823:( 798:) 795:y 792:, 789:x 786:( 783:f 759:2 755:n 751:+ 746:2 742:m 737:q 729:2 724:Z 716:) 713:n 710:, 707:m 704:( 672:1 669:= 664:2 660:y 656:n 648:2 644:x 615:2 611:y 607:3 599:2 595:x 591:, 586:2 582:y 578:2 575:+ 570:2 566:x 562:, 557:2 553:y 549:+ 544:2 540:x 517:2 513:y 509:3 501:2 497:x 493:= 490:p 468:2 464:y 460:2 452:2 448:x 444:= 441:p 419:2 415:y 411:3 408:+ 403:2 399:x 395:= 392:p 370:2 366:y 362:2 359:+ 354:2 350:x 346:= 343:p 322:) 319:4 312:( 307:1 301:p 279:2 275:y 271:+ 266:2 262:x 258:= 255:p 203:c 199:b 195:a 177:, 172:2 168:y 164:c 161:+ 158:y 155:x 152:b 149:+ 144:2 140:x 136:a 133:= 130:) 127:y 124:, 121:x 118:( 115:q 83:) 77:( 72:) 68:( 54:. 27:.

Index

integer
quadratic form
references
inline citations
improve
introducing
Learn how and when to remove this message
mathematics
homogeneous polynomial
complex numbers
quadratic form
integer
algebraic number theory
quadratic
number fields
Pell's equation
equivalence relation
partitioned
matrix
group action
discriminant
fundamental discriminant
subgroup
cyclic
Diophantus
Pell's equation
Euclid's Elements
sum of squares function
divisors
congruent

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.