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 16 results. Next

A259680 Let m = A062695(n); a(n) is value of s in decomposition of m defined in Comments.

Original entry on oeis.org

1, 1, 1, 137, 6, 29, 1, 1, 97, 5, 73, 1, 1, 1, 1, 1, 1, 17, 6, 1, 53, 1, 5, 41, 6, 2, 1, 1, 1, 101, 257, 7, 17, 1, 1, 7, 2, 337, 689, 7, 1, 1, 761, 37, 793, 1, 1, 1, 181, 61, 1, 21, 5, 1, 151, 1, 1, 1, 7, 1, 1, 1145, 2, 1, 11, 7, 2, 1, 593, 1, 1, 1217, 1, 1, 641
Offset: 1

Views

Author

N. J. A. Sloane, Jul 04 2015

Keywords

Comments

Let m = A062695(n). Write m*y^2 = x^3 - x as m*square = A*B*(A-B)*(A+B) where A and B are the numerator and denominator of x. Then A, B, A-B, A+B have the form s*a^2, t*b^2, u*c^2, v*d^2 for some decomposition of m as s*t*u*v and some natural numbers a,b,c,d. These eight numbers are given in A259680-A259687.

Crossrefs

Extensions

More terms from Jinyuan Wang, Jan 01 2021

A259687 Let m = A062695(n); a(n) is value of d in decomposition of m defined in Comments.

Original entry on oeis.org

1, 1, 1, 81, 5, 7, 1, 1, 13, 1, 11, 1, 185, 1, 1, 7, 1, 27, 1, 1, 9, 1, 9, 9, 11, 3, 15, 325, 1, 11, 17, 1, 1, 1, 1, 1, 5, 25, 33, 11, 7, 47, 801, 5, 193, 1, 1, 1, 19, 11, 13, 25, 21, 17, 635, 5, 37, 1, 1, 1, 1, 177, 23, 1, 1, 43, 9, 1, 5465, 27, 1, 2721, 1, 17
Offset: 1

Views

Author

N. J. A. Sloane, Jul 04 2015

Keywords

Comments

Let m = A062695(n). Write m*y^2 = x^3 - x as m*square = A*B*(A-B)*(A+B) where A and B are the numerator and denominator of x. Then A, B, A-B, A+B have the form s*a^2, t*b^2, u*c^2, v*d^2 for some decomposition of m as s*t*u*v and some natural numbers a,b,c,d. These eight numbers are given in A259680-A259687.

Crossrefs

Extensions

More terms from Jinyuan Wang, Jan 01 2021

A259681 Let m = A062695(n); a(n) is value of t in decomposition of m defined in Comments.

Original entry on oeis.org

2, 1, 1, 1, 1, 5, 2, 7, 2, 2, 3, 2, 1, 1, 3, 13, 1, 19, 5, 1, 7, 2, 1, 10, 1, 31, 26, 1, 15, 5, 2, 6, 1, 2, 1, 3, 47, 2, 1, 1, 3, 43, 1, 3, 1, 2, 7, 10, 5, 15, 1, 1, 1, 59, 1, 1, 1, 1, 1, 2, 13, 1, 191, 2, 1, 1, 31, 15, 2, 5, 1, 1, 1, 1, 2, 1, 5, 13, 2, 7, 19
Offset: 1

Views

Author

N. J. A. Sloane, Jul 04 2015

Keywords

Comments

Let m = A062695(n). Write m*y^2 = x^3 - x as m*square = A*B*(A-B)*(A+B) where A and B are the numerator and denominator of x. Then A, B, A-B, A+B have the form s*a^2, t*b^2, u*c^2, v*d^2 for some decomposition of m as s*t*u*v and some natural numbers a,b,c,d. These eight numbers are given in A259680-A259687.

Crossrefs

Extensions

More terms from Jinyuan Wang, Jan 01 2021

A259682 Let m = A062695(n); a(n) is value of u in decomposition of m defined in Comments.

Original entry on oeis.org

1, 1, 5, 1, 23, 1, 7, 1, 1, 3, 1, 1, 257, 5, 1, 23, 1, 1, 1, 1, 1, 1, 79, 1, 71, 1, 17, 457, 1, 1, 1, 1, 1, 7, 21, 1, 1, 1, 1, 103, 1, 17, 1, 1, 1, 1, 1, 1, 1, 1, 5, 47, 199, 1, 7, 37, 1081, 13, 3, 17, 3, 1, 3, 1, 7, 167, 19, 1, 1, 239, 1, 1, 1, 1, 1, 1, 1, 103
Offset: 1

Views

Author

N. J. A. Sloane, Jul 04 2015

Keywords

Comments

Let m = A062695(n). Write m*y^2 = x^3 - x as m*square = A*B*(A-B)*(A+B) where A and B are the numerator and denominator of x. Then A, B, A-B, A+B have the form s*a^2, t*b^2, u*c^2, v*d^2 for some decomposition of m as s*t*u*v and some natural numbers a,b,c,d. These eight numbers are given in A259680-A259687.

Crossrefs

Extensions

More terms from Jinyuan Wang, Jan 01 2021

A259683 Let m = A062695(n); a(n) is value of v in decomposition of m defined in Comments.

Original entry on oeis.org

17, 41, 13, 1, 1, 1, 11, 23, 1, 7, 1, 113, 1, 53, 97, 1, 313, 1, 11, 353, 1, 193, 1, 1, 1, 7, 1, 1, 31, 1, 1, 13, 33, 43, 29, 31, 7, 1, 1, 1, 241, 1, 1, 7, 1, 433, 127, 89, 1, 1, 197, 1, 1, 17, 1, 29, 1, 85, 53, 33, 29, 1, 1, 577, 15, 1, 1, 79, 1, 1, 1201, 1, 1241
Offset: 1

Views

Author

N. J. A. Sloane, Jul 04 2015

Keywords

Comments

Let m = A062695(n). Write m*y^2 = x^3 - x as m*square = A*B*(A-B)*(A+B) where A and B are the numerator and denominator of x. Then A, B, A-B, A+B have the form s*a^2, t*b^2, u*c^2, v*d^2 for some decomposition of m as s*t*u*v and some natural numbers a,b,c,d. These eight numbers are given in A259680-A259687.

Crossrefs

Extensions

More terms from Jinyuan Wang, Jan 01 2021

A259684 Let m = A062695(n); a(n) is value of a in decomposition of m defined in Comments.

Original entry on oeis.org

3, 5, 3, 5, 2, 1, 3, 4, 1, 1, 1, 9, 153, 7, 7, 6, 13, 5, 1, 17, 1, 11, 4, 1, 4, 4, 11, 253, 4, 1, 1, 1, 1, 5, 5, 2, 8, 1, 1, 4, 103, 39, 29, 2, 5, 19, 8, 7, 1, 1, 163, 4, 8, 63, 44, 23, 35, 7, 2, 5, 4, 5, 13, 17, 1, 12, 5, 8, 193, 22, 25, 65, 29, 481, 1, 85, 1
Offset: 1

Views

Author

N. J. A. Sloane, Jul 04 2015

Keywords

Comments

Let m = A062695(n). Write m*y^2 = x^3 - x as m*square = A*B*(A-B)*(A+B) where A and B are the numerator and denominator of x. Then A, B, A-B, A+B have the form s*a^2, t*b^2, u*c^2, v*d^2 for some decomposition of m as s*t*u*v and some natural numbers a,b,c,d. These eight numbers are given in A259680-A259687.

Crossrefs

Extensions

More terms from Jinyuan Wang, Jan 01 2021

A259685 Let m = A062695(n); a(n) is value of b in decomposition of m defined in Comments.

Original entry on oeis.org

2, 4, 2, 56, 1, 2, 1, 1, 6, 1, 4, 4, 104, 2, 4, 1, 12, 4, 1, 8, 2, 6, 1, 2, 5, 1, 2, 204, 1, 2, 4, 1, 4, 3, 2, 1, 1, 12, 20, 3, 20, 4, 40, 3, 132, 6, 3, 2, 6, 2, 82, 17, 11, 4, 333, 14, 12, 6, 5, 2, 1, 52, 1, 12, 2, 29, 1, 1, 1972, 7, 24, 1504, 20, 360, 10, 2952
Offset: 1

Views

Author

N. J. A. Sloane, Jul 04 2015

Keywords

Comments

Let m = A062695(n). Write m*y^2 = x^3 - x as m*square = A*B*(A-B)*(A+B) where A and B are the numerator and denominator of x. Then A, B, A-B, A+B have the form s*a^2, t*b^2, u*c^2, v*d^2 for some decomposition of m as s*t*u*v and some natural numbers a,b,c,d. These eight numbers are given in A259680-A259687.

Crossrefs

Extensions

More terms from Jinyuan Wang, Jan 01 2021

A259686 Let m = A062695(n); a(n) is value of c in decomposition of m defined in Comments.

Original entry on oeis.org

1, 3, 1, 17, 1, 3, 1, 3, 5, 1, 5, 7, 7, 3, 1, 1, 5, 11, 1, 15, 5, 7, 1, 1, 1, 1, 1, 7, 1, 9, 15, 1, 1, 1, 1, 5, 9, 7, 17, 1, 97, 7, 799, 11, 49, 17, 1, 3, 1, 1, 63, 1, 1, 55, 161, 3, 1, 1, 1, 1, 1, 161, 7, 1, 1, 1, 1, 7, 3783, 1, 7, 1697, 21, 319, 21, 911, 3, 1
Offset: 1

Views

Author

N. J. A. Sloane, Jul 04 2015

Keywords

Comments

Let m = A062695(n). Write m*y^2 = x^3 - x as m*square = A*B*(A-B)*(A+B) where A and B are the numerator and denominator of x. Then A, B, A-B, A+B have the form s*a^2, t*b^2, u*c^2, v*d^2 for some decomposition of m as s*t*u*v and some natural numbers a,b,c,d. These eight numbers are given in A259680-A259687.

Crossrefs

Extensions

More terms from Jinyuan Wang, Jan 01 2021

A194687 Least k such that the rank of the elliptic curve y^2 = x^3 - k^2*x is n, or -1 if no such k exists.

Original entry on oeis.org

1, 5, 34, 1254, 29274, 48272239, 6611719866
Offset: 0

Views

Author

Keywords

Comments

Fermat found a(0), Biling found a(1), and Wiman found a(2)-a(4). Rogers found upper bounds on a(5) and a(6) equal to their true value; Rathbun and an unknown author verified them as a(5) and a(6), respectively.
a(7) <= 797507543735, see Rogers 2004.

References

  • G. Billing, "Beiträge zur arithmetischen theorie der ebenen kubischen kurven geschlechteeins", Nova Acta Reg. Soc. Sc. Upsaliensis (4) 11 (1938), Nr. 1. Diss. 165 S.
  • N. Rogers, "Elliptic curves x^3 + y^2 = k with high rank", PhD Thesis in Mathematics, Harvard University (2004).
  • A. Wiman, "Über rationale Punkte auf Kurven y^2 = x(x^2-c^2)", Acta Math. 77 (1945), pp. 281-320.

Crossrefs

Programs

  • PARI
    r(n)=ellanalyticrank(ellinit([0,0,0,-n^2,0]))[1]
    rec=0;for(n=1,1e4,t=r(n);if(t>rec,rec=t;print("r("n") = "t)))

Extensions

Escape clause added to definition by N. J. A. Sloane, Jul 01 2024

A273929 Numbers that are congruent to {5, 6, 7} mod 8 and are squarefree.

Original entry on oeis.org

5, 6, 7, 13, 14, 15, 21, 22, 23, 29, 30, 31, 37, 38, 39, 46, 47, 53, 55, 61, 62, 69, 70, 71, 77, 78, 79, 85, 86, 87, 93, 94, 95, 101, 102, 103, 109, 110, 111, 118, 119, 127, 133, 134, 141, 142, 143, 149, 151, 157, 158, 159, 165, 166, 167, 173, 174
Offset: 1

Views

Author

Frank M Jackson, Jun 04 2016

Keywords

Comments

It has been shown, conditional on the Birch Swinnerton-Dyer conjecture, that this sequence is a subset of the primitive congruent numbers (A006991). The union of this sequence with A062695 gives A006991. Also this sequence is the intersection of A047574 and A005117.
The asymptotic density of this sequence is 3/Pi^2 (A104141). - Amiram Eldar, Mar 09 2021

Crossrefs

Programs

  • Magma
    [n: n in [1..250] | n mod 8 in [5, 6, 7] and IsSquarefree(n)]; // Vincenzo Librandi, Jun 06 2016
  • Mathematica
    Select[Range[1000], MemberQ[{5, 6, 7}, Mod[#, 8]] && SquareFreeQ[#] &]
  • PARI
    is(n) = n % 8 > 4 && issquarefree(n) \\ Felix Fröhlich, Jun 04 2016
    
Showing 1-10 of 16 results. Next