A022673 Expansion of Product_{m >= 1} (1-m*q^m)^13.

1, -13, 52, 13, -546, 676, 1911, -962, -9282, -13624, 53027, 57408, -48334, -222912, -558402, 517803, 1776723, 2996227, -1100554, -14813461, -12542478, -3043521, 50552853, 110798116, 84474624, -114111322, -650898679, -771617782, -206121175, 1974416808, 4748905980, 5776813289

Offset: 0

Author

N. J. A. Sloane

Keywords

• sign

Links

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

Programs

Magma

Coefficients(&*[(1-m*x^m)^13:m in [1..40]])[1..40] where x is PolynomialRing(Integers()).1; // G. C. Greubel, Feb 24 2018

Mathematica

With[{nmax = 50}, CoefficientList[Series[Product[(1 - k*q^k)^13, {k, 1, nmax}], {q, 0, nmax}], q]] (* G. C. Greubel, Feb 24 2018 *)

PARI

m=50; q='q+O('q^m); Vec(prod(n=1,m,(1-n*q^n)^13)) \\ G. C. Greubel, Feb 24 2018

Extensions

Terms a(26) onward added by G. C. Greubel, Feb 24 2018