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 1-8 of 8 results.

A284474 Expansion of Product_{k>=1} (1 + x^(2*k))^(2*k)/(1 + x^(2*k-1))^(2*k-1).

Original entry on oeis.org

1, -1, 3, -6, 11, -22, 42, -74, 131, -231, 395, -669, 1122, -1851, 3029, -4915, 7891, -12572, 19881, -31203, 48657, -75391, 116096, -177792, 270822, -410394, 618905, -929052, 1388403, -2066140, 3062270, -4520912, 6649463, -9745072, 14232278, -20716355, 30057438
Offset: 0

Views

Author

Seiichi Manyama, Apr 15 2017

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 50; CoefficientList[Series[Product[(1 + x^(2*k))^(2*k)/(1 + x^(2*k-1))^(2*k-1), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Apr 15 2017 *)

Formula

a(n) ~ (-1)^n * exp(-1/12 + 3 * 2^(-5/3) * (7*Zeta(3))^(1/3) * n^(2/3)) * A * (7*Zeta(3))^(5/36) / (2^(10/9) * sqrt(3*Pi) * n^(23/36)), where A is the Glaisher-Kinkelin constant A074962. - Vaclav Kotesovec, Apr 17 2017
G.f.: exp(Sum_{k>=1} (-1)^k*x^k/(k*(1 + x^k)^2)). - Ilya Gutkovskiy, Jun 20 2018

A285287 Expansion of Product_{k>=0} 1/(1 + x^(4*k+1))^(4*k+1).

Original entry on oeis.org

1, -1, 1, -1, 1, -6, 6, -6, 6, -15, 30, -30, 30, -43, 88, -123, 123, -140, 250, -385, 455, -476, 678, -1098, 1413, -1564, 1913, -2918, 4048, -4707, 5452, -7572, 10747, -13265, 15195, -19534, 27349, -35146, 41042, -50011, 67596, -88897, 106519, -126635, 164230
Offset: 0

Views

Author

Seiichi Manyama, Apr 16 2017

Keywords

Crossrefs

Product_{k>=0} 1/(1 + x^(m*k+1))^(m*k+1): A284628 (m=2), A285286 (m=3), this sequence (m=4).

Programs

  • Mathematica
    nmax = 50; CoefficientList[Series[Product[1/(1 + x^(4*k-3))^(4*k-3), {k,1,nmax}], {x,0,nmax}], x] (* Vaclav Kotesovec, Apr 16 2017 *)

Formula

a(n) = (-1)^n * A285048(n).

A292038 Expansion of Product_{k>=1} ((1 + x^(2*k-1)) / (1 - x^(2*k-1)))^(2*k-1).

Original entry on oeis.org

1, 2, 2, 8, 14, 24, 52, 84, 158, 274, 464, 800, 1316, 2208, 3576, 5832, 9358, 14876, 23614, 36936, 57752, 89336, 137716, 210844, 321148, 486890, 733912, 1102336, 1646736, 2451464, 3632832, 5363988, 7889710, 11562712, 16888748, 24581904, 35670242, 51591096
Offset: 0

Views

Author

Vaclav Kotesovec, Sep 08 2017

Keywords

Comments

Convolution of A262736 and A262811.

Crossrefs

Programs

  • Mathematica
    nmax = 50; CoefficientList[Series[Product[((1+x^(2*k-1))/(1-x^(2*k-1)))^(2*k-1), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

a(n) ~ exp(3*(7*Zeta(3))^(1/3)*n^(2/3) / 2^(5/3) - 1/12) * A * (7*Zeta(3))^(5/36) / (2^(31/36) * sqrt(3*Pi) * n^(23/36)), where A is the Glaisher-Kinkelin constant A074962.
G.f.: exp(2*Sum_{k>=1} sigma_2(2*k - 1)*x^(2*k-1)/(2*k - 1)). - Ilya Gutkovskiy, Apr 19 2019

A285311 Expansion of Product_{k>=0} 1/(1 + x^(4*k+3))^(4*k+3).

Original entry on oeis.org

1, 0, 0, -3, 0, 0, 6, -7, 0, -10, 21, -11, 15, -42, 61, -36, 70, -150, 150, -124, 278, -441, 375, -468, 909, -1131, 1018, -1581, 2602, -2810, 2947, -4819, 6768, -6980, 8509, -13389, 16788, -17609, 23722, -34720, 40337, -44863, 63128, -85430, 95887, -114037
Offset: 0

Views

Author

Seiichi Manyama, Apr 16 2017

Keywords

Crossrefs

Product_{k>=0} 1/(1 + x^(m*k+m-1))^(m*k+m-1): A284628 (m=2), A285310 (m=3), this sequence (m=4).
Cf. A285131.

Formula

a(n) = (-1)^n * A285131(n).

A285286 Expansion of Product_{k>=0} 1/(1 + x^(3*k+1))^(3*k+1).

Original entry on oeis.org

1, -1, 1, -1, -3, 3, -3, -4, 14, -14, 4, 24, -44, 31, 37, -107, 126, -4, -208, 329, -175, -319, 777, -704, -236, 1507, -1945, 430, 2532, -4575, 2781, 3236, -9301, 8697, 2085, -16902, 21804, -5233, -26573, 47225, -27047, -34332, 92242, -80162, -26926, 162426
Offset: 0

Views

Author

Seiichi Manyama, Apr 16 2017

Keywords

Crossrefs

Product_{k>=0} 1/(1 + x^(m*k+1))^(m*k+1): A284628 (m=2), this sequence (m=3), A285287 (m=4).
Cf. A262949.

Programs

  • Mathematica
    nmax = 50; CoefficientList[Series[Product[1/(1 + x^(3*k-2))^(3*k-2), {k,1,nmax}], {x,0,nmax}], x] (* Vaclav Kotesovec, Apr 16 2017 *)

A285294 Expansion of Product_{k>=1} (1 + x^(3*k))^(3*k) / (1 + x^k)^k.

Original entry on oeis.org

1, -1, -1, 1, -2, -3, 7, -4, -1, 20, -9, -15, 45, -39, -38, 95, -81, -99, 244, -196, -188, 538, -371, -421, 1256, -823, -820, 2575, -1672, -1904, 5367, -3714, -3861, 10555, -7362, -8159, 21391, -14975, -15592, 41654, -28293, -30748, 82026, -54899, -57331, 155933
Offset: 0

Views

Author

Seiichi Manyama, Apr 16 2017

Keywords

Crossrefs

Product_{k>=1} (1 + x^(m*k))^(m*k) / (1 + x^k)^k: A284628 (m=2), this sequence (m=3), A285295 (m=4).
Cf. A262924.

Programs

  • Mathematica
    nmax = 50; CoefficientList[Series[Product[(1 + x^(3*k))^(3*k) / (1 + x^k)^k, {k,1,nmax}], {x,0,nmax}], x] (* Vaclav Kotesovec, Apr 16 2017 *)

A285295 Expansion of Product_{k>=1} (1 + x^(4*k))^(4*k) / (1 + x^k)^k.

Original entry on oeis.org

1, -1, -1, -2, 5, -4, 0, -6, 26, -16, 6, -31, 93, -81, 19, -147, 310, -295, 136, -486, 1069, -940, 645, -1575, 3338, -3021, 2301, -5089, 9735, -9381, 7548, -15506, 27556, -27587, 23664, -44862, 76043, -77620, 70982, -124744, 204389, -211376, 203644, -336775
Offset: 0

Views

Author

Seiichi Manyama, Apr 16 2017

Keywords

Crossrefs

Product_{k>=1} (1 + x^(m*k))^(m*k) / (1 + x^k)^k: A284628 (m=2), A285294 (m=3), this sequence (m=4).
Cf. A285292.

Programs

  • Mathematica
    nmax = 50; CoefficientList[Series[Product[(1 + x^(4*k))^(4*k) / (1 + x^k)^k, {k,1,nmax}], {x,0,nmax}], x] (* Vaclav Kotesovec, Apr 16 2017 *)

Formula

a(n) ~ (-1)^n * exp(-1/12 + 3 * (5*Zeta(3))^(1/3) * n^(2/3) / 4) * A * (5*Zeta(3))^(5/36) / (2^(5/4) * sqrt(3*Pi) * n^(23/36)), where A is the Glaisher-Kinkelin constant A074962. - Vaclav Kotesovec, Apr 17 2017

A285310 Expansion of Product_{k>=0} 1/(1 + x^(3*k+2))^(3*k+2).

Original entry on oeis.org

1, 0, -2, 0, 3, -5, -4, 10, -3, -15, 25, 9, -47, 37, 55, -118, 28, 182, -231, -88, 484, -351, -474, 1047, -306, -1479, 1985, 370, -3657, 3120, 2757, -7868, 3686, 8889, -14950, 1255, 22540, -25069, -9557, 49333, -35638, -40172, 96943, -37509, -111145, 172256
Offset: 0

Views

Author

Seiichi Manyama, Apr 16 2017

Keywords

Crossrefs

Product_{k>=0} 1/(1 + x^(m*k+m-1))^(m*k+m-1): A284628 (m=2), this sequence (m=3), A285311 (m=4).
Showing 1-8 of 8 results.