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 1-5 of 5 results.

A262736 Expansion of Product_{k>=1} (1 + x^(2*k-1))^(2*k-1).

Original entry on oeis.org

1, 1, 0, 3, 3, 5, 8, 10, 22, 25, 41, 57, 88, 126, 168, 261, 351, 512, 685, 984, 1357, 1865, 2566, 3485, 4838, 6459, 8832, 11831, 16056, 21404, 28660, 38259, 50875, 67613, 89161, 118184, 155321, 204609, 267708, 351125, 458331, 597740, 777590, 1010020, 1310390
Offset: 0

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Author

Vaclav Kotesovec, Sep 29 2015

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 60; CoefficientList[Series[Product[(1 + x^(2*k-1))^(2*k-1), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

a(n) ~ exp(3^(4/3) * (Zeta(3))^(1/3) * n^(2/3) / 2^(5/3)) * Zeta(3)^(1/6) / (2^(3/4) * 3^(1/3) * sqrt(Pi) * n^(2/3)).

A262924 Expansion of Product_{k>=1} (1 + x^(3*k-1))^(3*k-1) * (1 + x^(3*k-2))^(3*k-2).

Original entry on oeis.org

1, 1, 2, 2, 5, 10, 13, 25, 35, 57, 87, 134, 211, 306, 458, 684, 996, 1465, 2129, 3073, 4411, 6288, 8977, 12707, 17913, 25185, 35231, 49078, 68228, 94490, 130408, 179425, 246121, 336681, 459239, 624842, 847986, 1147728, 1549773, 2087972, 2806455, 3764136
Offset: 0

Views

Author

Vaclav Kotesovec, Oct 04 2015

Keywords

Comments

Convolution of A262948 and A262949.

Crossrefs

Programs

  • Mathematica
    nmax=60; CoefficientList[Series[Product[(1 + x^(3*k-1))^(3*k-1)*(1 + x^(3*k-2))^(3*k-2), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

a(n) ~ exp(3*Zeta(3)^(1/3)*n^(2/3)/2) * Zeta(3)^(1/6) / (2^(1/3) * sqrt(3*Pi) * n^(2/3)).

A285293 Expansion of Product_{k>=1} (1 + x^k)^k / (1 + x^(5*k))^(5*k).

Original entry on oeis.org

1, 1, 2, 5, 8, 11, 23, 39, 58, 102, 160, 250, 392, 614, 929, 1426, 2155, 3221, 4816, 7124, 10516, 15389, 22448, 32549, 47027, 67586, 96779, 138052, 196078, 277606, 391570, 550516, 771442, 1077818, 1501214, 2084899, 2887759, 3988792, 5495381, 7552127, 10353345
Offset: 0

Views

Author

Vaclav Kotesovec, Apr 16 2017

Keywords

Comments

In general, if m > 1 and g.f. = Product_{k>=1} (1 + x^k)^k / (1 + x^(m*k))^(m*k), then a(n, m) ~ exp(2^(-4/3) * 3^(4/3) * (1-1/m)^(1/3) * Zeta(3)^(1/3) * n^(2/3)) * 2^(m/12 - 3/4) * (1-1/m)^(1/6) * Zeta(3)^(1/6) / (3^(1/3) * sqrt(Pi) * n^(2/3)).

Crossrefs

Cf. A262736 (m=2), A262924 (m=3), A285292 (m=4).

Programs

  • Mathematica
    nmax = 50; CoefficientList[Series[Product[(1+x^k)^k/(1+x^(5*k))^(5*k), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

a(n) ~ exp(2^(-2/3) * 3^(4/3) * 5^(-1/3) * Zeta(3)^(1/3) * n^(2/3)) * Zeta(3)^(1/6) / (3^(1/3) * 5^(1/6) * sqrt(Pi) * n^(2/3)).

A285284 Expansion of Product_{k>=1} (1 - x^k)^k/(1 - x^(4*k))^(4*k).

Original entry on oeis.org

1, -1, -2, -1, 4, 0, -4, 3, 21, -4, -29, -7, 51, -24, -105, -7, 201, -30, -291, 34, 642, -42, -874, 75, 1764, -262, -2737, -40, 4555, -818, -7512, 88, 12425, -1492, -19062, 1135, 32637, -2573, -47688, 3576, 81335, -6477, -119540, 6525, 193738, -18478, -292685
Offset: 0

Views

Author

Seiichi Manyama, Apr 16 2017

Keywords

Crossrefs

Product_{k>=1} (1 - x^k)^k/(1 - x^(m*k))^(m*k): A285069 (m=2), A285247 (m=3), this sequence (m=4), A285285 (m=5).

Programs

  • Mathematica
    nmax = 50; CoefficientList[Series[Product[(1 - x^k)^k/(1 - x^(4*k))^(4*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
Showing 1-5 of 5 results.