A022678 Expansion of Product_{m>=1} (1-m*q^m)^18.

1, -18, 117, -222, -936, 4680, -951, -23634, 4815, 89692, 170019, -583992, -1009011, 1753434, 3755619, 3911748, -16001739, -35135352, 6931209, 99524520, 287076168, -92384118, -969330771, -1271547612, -41096046

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)^18:m in [1..40]])[1..40] where x is PolynomialRing(Integers()).1; // G. C. Greubel, Jul 18 2018

Mathematica

With[{nmax = 50}, CoefficientList[Series[Product[(1 - k*q^k)^18, {k, 1, nmax}], {q, 0, nmax}], q]] (* G. C. Greubel, Jul 18 2018 *)

PARI

m=50; q='q+O('q^m); Vec(prod(n=1,m,(1-n*q^n)^18)) \\ G. C. Greubel, Jul 18 2018