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 1-3 of 3 results.

A285070 Expansion of Product_{k>=0} (1-x^(4*k+1))^(4*k+1).

Original entry on oeis.org

1, -1, 0, 0, 0, -5, 5, 0, 0, -9, 19, -10, 0, -13, 58, -55, 10, -17, 118, -191, 95, -26, 223, -512, 400, -116, 362, -1175, 1329, -564, 609, -2368, 3593, -2218, 1246, -4402, 8600, -7118, 3433, -7792, 18503, -19778, 10702, -13924, 37009, -49017, 32097, -27141
Offset: 0

Views

Author

Seiichi Manyama, Apr 15 2017

Keywords

Links

Crossrefs

Product_{k>=0} (1-x^(m*k+1))^(m*k+1): A285069 (m=2), A285050 (m=3), this sequence (m=4), A285071 (m=5).
Cf. A285048, A285288.

Programs

  • Mathematica
    nmax = 50; CoefficientList[Series[Product[(1-x^(4*k-3))^(4*k-3), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Apr 17 2017 *)

Formula

a(n) ~ (-1)^n * exp(3^(4/3) * Zeta(3)^(1/3) * n^(2/3) / 4) * Zeta(3)^(1/6) / (2^(23/24) * 3^(1/3) * sqrt(Pi) * n^(2/3)). - Vaclav Kotesovec, Apr 17 2017

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

Links

Crossrefs

Product_{k>=0} 1/(1 + x^(m*k+1))^(m*k+1): A284628 (m=2), A285286 (m=3), this sequence (m=4).
Cf. A285048, A285288.

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).

A285338 Expansion of Product_{k>=1} (1 + x^(5*k-4))^(5*k-4).

Original entry on oeis.org

1, 1, 0, 0, 0, 0, 6, 6, 0, 0, 0, 11, 26, 15, 0, 0, 16, 82, 86, 20, 0, 21, 172, 316, 180, 15, 26, 328, 872, 790, 226, 37, 538, 2043, 2681, 1310, 202, 845, 4184, 7426, 5390, 1447, 1290, 7855, 18067, 17705, 7277, 2662, 13723, 39468, 50030, 28707, 8742, 22979, 79760
Offset: 0

Views

Author

Vaclav Kotesovec, Apr 17 2017

Keywords

Comments

For all n<=30 a(n) = abs(A285071(n)), but a(31) <> abs(A285071(31)).
In general, if m >= 1 and g.f. = Product_{k>=1} (1 + x^(m*k-m+1))^(m*k-m+1), then a(n, m) ~ exp(2^(-4/3) * 3^(4/3) * m^(-1/3) * Zeta(3)^(1/3) * n^(2/3)) * Zeta(3)^(1/6) / (2^(1/6 + 1/(2*m) + m/12) * 3^(1/3) * m^(1/6) * sqrt(Pi) * n^(2/3)).

Links

Crossrefs

Product_{k>=0} (1 + x^(m*k+1))^(m*k+1): A026007 (m=1), A262736 (m=2), A262949 (m=3), A285288 (m=4), this sequence (m=5).
Cf. A285071, A285340.

Programs

  • Mathematica
    nmax = 50; CoefficientList[Series[Product[(1+x^(5*k-4))^(5*k-4), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

a(n) ~ exp(2^(-4/3) * 3^(4/3) * 5^(-1/3) * Zeta(3)^(1/3) * n^(2/3)) * Zeta(3)^(1/6) / (2^(41/60) * 3^(1/3) * 5^(1/6) * sqrt(Pi) * n^(2/3)).
Showing 1-3 of 3 results.

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