cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-10 of 12 results. Next

A060950 Rank of elliptic curve y^2 = x^3 + n.

Original entry on oeis.org

0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 2, 0, 2, 1, 1, 0, 0, 1, 0, 2, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, 2, 1, 1, 1, 1, 0, 2, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 2, 1, 0, 0, 1, 1, 2, 0, 2, 1, 1, 1, 1, 0, 1, 1, 2, 1, 0, 1, 1, 0, 2, 1, 0, 1, 1, 0, 0, 0, 0, 0, 2, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1
Offset: 1

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Author

N. J. A. Sloane, May 10 2001

Keywords

Comments

The curves for n and -27*n are isogenous (as Noam Elkies points out--see Womack), so they have the same rank. - Jonathan Sondow, Sep 10 2013

Examples

			a(1) = A060951(27) = a(729) = 0. - _Jonathan Sondow_, Sep 10 2013
		

Crossrefs

Cf. A081119 (number of integral solutions to Mordell's equation y^2 = x^3 + n).

Programs

  • PARI
    a(n) = ellanalyticrank(ellinit([0, 0, 0, 0, n]))[1] \\ Jianing Song, Aug 24 2022
    
  • PARI
    apply( {A060950(n)=ellrank(ellinit([0, n]))[1]}, [1..99]) \\ For PARI version  < 2.14, use ellanalyticrank(...). - M. F. Hasler, Jul 01 2024

Formula

a(n) = A060951(27*n) and A060951(n) = a(27*n), so a(n) = a(729*n). - Jonathan Sondow, Sep 10 2013

Extensions

Corrected by James R. Buddenhagen, Feb 18 2005

A002155 Numbers k for which the rank of the elliptic curve y^2 = x^3 + k is 2.

Original entry on oeis.org

15, 17, 24, 37, 43, 57, 63, 65, 73, 79, 89, 101, 106, 122, 129, 131, 142, 145, 148, 151, 161, 164, 168, 171, 186, 195, 197, 198, 204, 217, 222, 223, 225, 229, 232, 233, 248, 252, 260, 265, 268, 269, 281, 294, 295, 297, 303, 322, 331, 337, 347, 350, 353, 360, 366, 369, 373, 377, 381, 388, 389, 392, 404, 409, 412, 414, 433, 449, 464, 469, 481, 483, 485, 492
Offset: 1

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Author

Keywords

References

  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Programs

  • Magma
    for k in[1..500] do if Rank(EllipticCurve([0,0,0,0,k])) eq 2 then print k; end if; end for; // Vaclav Kotesovec, Jul 07 2019

Extensions

More terms from James R. Buddenhagen, Feb 18 2005

A002153 Numbers k for which the rank of the elliptic curve y^2 = x^3 + k is 1.

Original entry on oeis.org

2, 3, 5, 8, 9, 10, 11, 12, 18, 19, 22, 26, 28, 30, 31, 33, 35, 36, 38, 39, 40, 41, 44, 46, 47, 48, 50, 52, 54, 55, 56, 58, 61, 62, 66, 67, 68, 69, 71, 72, 74, 76, 77, 80, 82, 83, 91, 92, 94, 97, 98, 99, 100, 102, 103, 105, 107, 108, 110, 111, 112, 117, 118, 119
Offset: 1

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Author

Keywords

References

  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Programs

  • Magma
    for k in[1..200] do if Rank(EllipticCurve([0,0,0,0,k])) eq 1 then print k; end if; end for; // Vaclav Kotesovec, Jul 07 2019

Extensions

Corrected and extended by James R. Buddenhagen, Feb 18 2005

A102833 Numbers n for which rank of the elliptic curve y^2=x^3+n is 3.

Original entry on oeis.org

113, 141, 316, 346, 359, 427, 443, 506, 537, 568, 659, 681, 730, 745, 873, 892, 899, 940, 997, 1016, 1025, 1090, 1149, 1157, 1171, 1213, 1304, 1305, 1342, 1367, 1373, 1478, 1522, 1639, 1646, 1737, 1753, 1772, 1811, 1841, 1897, 1907, 1954, 2024, 2143
Offset: 1

Views

Author

James R. Buddenhagen, Feb 18 2005. Entry revised by N. J. A. Sloane, Jun 10 2012

Keywords

Crossrefs

Programs

  • Magma
    for k in[1..2000] do if Rank(EllipticCurve([0,0,0,0,k])) eq 3 then print k; end if; end for; // Vaclav Kotesovec, Jul 07 2019

Extensions

More terms from T. D. Noe, Jul 24 2007

A179124 Parameters n for which the elliptic curve y^2=x^3+n has rank 4.

Original entry on oeis.org

2089, 3391, 4481, 4910, 6856, 7057, 7954, 9052, 10333, 10636, 10942, 11321, 11665, 12092, 12742, 13191, 13897, 14129, 14668, 15193, 15501, 15641, 15661, 15689, 16306, 16376, 16649
Offset: 1

Views

Author

Artur Jasinski, Jun 30 2010

Keywords

Comments

See A031507 for the smallest n such that rank of the elliptic curve y^2=x^3+n is some given k.

Crossrefs

Cf. A002151 (rank 0), A002153 (rank 1), A002155 (rank 2), A102833 (rank 3), A031507.

Extensions

a(9)-a(27) from Seiichi Manyama, Jul 07 2019

A179127 Numbers n for which the order of Tate-Shafarevich group Ш (Sha) of the elliptic curve y^2=x^3+n is 4.

Original entry on oeis.org

123, 174, 214, 231, 286, 362, 383, 445, 487, 510, 527, 546, 566, 571, 608, 627, 669, 706, 718, 734, 741, 762, 805, 914, 942, 965, 970, 1019, 1042, 1059, 1075, 1131, 1155, 1166, 1189, 1203, 1210, 1230, 1236, 1245, 1287, 1320, 1355, 1392, 1397, 1410, 1411
Offset: 1

Views

Author

Artur Jasinski, Jun 30 2010

Keywords

Comments

For n<123 the order of the Tate-Shafarevich group Ш of the elliptic curve y^2=x^3+n is 1.

Crossrefs

Extensions

Edited by N. J. A. Sloane, Jul 05 2010

A179125 a(n) = A000037(n)^3.

Original entry on oeis.org

8, 27, 125, 216, 343, 512, 1000, 1331, 1728, 2197, 2744, 3375, 4913, 5832, 6859, 8000, 9261, 10648, 12167, 13824, 17576, 19683, 21952, 24389, 27000, 29791, 32768, 35937, 39304, 42875, 50653, 54872, 59319, 64000, 68921, 74088, 79507, 85184, 91125
Offset: 1

Views

Author

Artur Jasinski, Jun 30 2010

Keywords

Comments

Parameters n for which the torsion subgroup of the elliptic curve y^2=x^3+n has order 2.
Numbers which are perfect cubes (A000578) but not perfect squares (A000290).

Crossrefs

Programs

  • Magma
    [(n+Floor(1/2+Sqrt(n)))^3: n in [1..60]]; // Vincenzo Librandi, Apr 11 2020
    
  • Mathematica
    a[n_]:=(n + Floor[1/2 + Sqrt[n]])^3; Array[a,50] (* Vincenzo Librandi, Apr 11 2020 *)
  • PARI
    isok(n) = !issquare(n) && ispower(n, 3); \\ Michel Marcus, Nov 02 2013
    
  • PARI
    a(n) = (n + (1+sqrtint(4*n))\2)^3; \\ Michel Marcus, Nov 02 2013
    
  • Python
    from math import isqrt
    def A179125(n): return (n+(k:=isqrt(n))+int(n>k*(k+1)))**3 # Chai Wah Wu, Jun 05 2025

Formula

Sum_{n>=1} 1/a(n) = zeta(3) - zeta(6) = A002117 - A013664 = 0.1847138411... - Amiram Eldar, Nov 21 2020

Extensions

Exponent in the definition corrected by R. J. Mathar, Jul 20 2010

A179126 Positive integers m for which the torsion subgroup of the elliptic curve y^2 = x^3 + m has order 3.

Original entry on oeis.org

4, 9, 16, 25, 36, 49, 81, 100, 121, 144, 169, 196, 225, 256, 289, 324, 361, 400, 441, 484, 529, 576, 625, 676, 784, 841, 900, 961, 1024, 1089, 1156, 1225, 1296, 1369, 1444, 1521, 1600, 1681, 1764, 1849, 1936, 2025, 2116, 2209, 2304, 2401, 2500, 2601, 2704
Offset: 1

Views

Author

Artur Jasinski, Jun 30 2010

Keywords

Comments

Apparently equal to the set of integers (A004709(k))^2, k>=2. [This is incorrect, as shown by the terms 256, 576, 1024, 1600, and 2304. - Jianing Song, Aug 25 2022]
From Jianing Song, Aug 25 2022: (Start)
Numbers which are perfect squares (A000290) but not perfect cubes (A000578). This follows from the complete description of the torsion group of y^2 = x^3 + n, using O to denote the point at infinity (see Exercise 10.19 of Chapter X of Silverman's Arithmetic of elliptic curves):
- If n = t^6 is a sixth power, then the torsion group consists of O, (2*t^2,+-3*t^3), (0,+-t^3), and (-t^2, 0).
- If n = t^2 is not a sixth power, then the torsion group consists of O and (0,+-t).
- If n = t^3 is not a sixth power, then the torsion group consists of O and (-t,0).
- If n is of the form -432*t^6, then the torsion group consists of O and (12*t^2,+-36*t^3).
- In all the other cases, the torsion group is trivial. (End)

Crossrefs

Programs

A179128 Numbers n for which order of Tate-Shafarevich group Ш of the elliptic curve y^2=x^3+n is 5.

Original entry on oeis.org

8798, 9834
Offset: 1

Views

Author

Artur Jasinski, Jun 30 2010

Keywords

Comments

For n<123 order of Tate-Shafarevich group Ш of the elliptic curve y^2=x^3+n is 1.
For #Ш=4 see A179127.

Crossrefs

A179130 Parameters k for which the Tate-Shafarevich group Ш of the elliptic curve y^2=x^3+k has order 16.

Original entry on oeis.org

3686, 4010, 4631, 4694, 5730, 6395, 6467, 6493, 7221, 7683, 8222, 8726, 8950, 9237, 9762, 9951, 9965
Offset: 1

Views

Author

Artur Jasinski, Jun 30 2010

Keywords

Comments

For parameters k<123, the order of the Tate-Shafarevich group Ш of the elliptic curve y^2=x^3+k is 1.

Crossrefs

Cf. A002151, A002153, A002155, A031507, A179127 (order 4), A179128 (order 5), A179129 (order 9), A179138-A179144.
Showing 1-10 of 12 results. Next