A022687 Expansion of Product_{m>=1} (1-m*q^m)^27.

1, -27, 297, -1548, 2079, 18036, -88893, 42471, 632259, -1042392, -2491695, 3171771, 19897479, -6178491, -149788494, 40753548, 598051971, 397032246, -1758684468, -5331986973, 4009289778, 22014953235

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)^27:m in [1..40]])[1..40] where x is PolynomialRing(Integers()).1; // G. C. Greubel, Jul 19 2018

Mathematica

With[{nmax = 50}, CoefficientList[Series[Product[(1 - k*q^k)^27, {k, 1, nmax}], {q, 0, nmax}], q]] (* G. C. Greubel, Jul 19 2018 *)

PARI

m=50; q='q+O('q^m); Vec(prod(n=1,m,(1-n*q^n)^27)) \\ G. C. Greubel, Jul 19 2018