A022713 - OEIS

A022713

Expansion of Product_{m>=1} (1+m*q^m)^-21.

1, -21, 189, -952, 3087, -8400, 27503, -92907, 246981, -588490, 1649823, -4645179, 10989769, -25476717, 65615424, -161705810, 363998754, -834169539, 1973130271, -4510112565, 9969930495, -22054706773

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OFFSET

0,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..1000

MATHEMATICA

With[{nmax = 50}, CoefficientList[Series[Product[(1 + k*q^k)^-21, {k, 1, nmax}], {q, 0, nmax}], q]] (* G. C. Greubel, Jul 20 2018 *)

PROG

(PARI) m=50; q='q+O('q^m); Vec(prod(n=1, m, (1+n*q^n)^-21)) \\ G. C. Greubel, Jul 20 2018

CROSSREFS

Sequence in context: A274653 A223090 A010827 * A163718 A164606 A027780

Adjacent sequences: A022710 A022711 A022712 * A022714 A022715 A022716

KEYWORD

sign

AUTHOR

N. J. A. Sloane

STATUS

approved