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)^20, {k, 1, nmax}], {q, 0, nmax}], q]] (* G. C. Greubel, Jul 18 2018 *)
PROG
(PARI) m=50; q='q+O('q^m); Vec(prod(n=1, m, (1-n*q^n)^20)) \\ G. C. Greubel, Jul 18 2018
(Magma) Coefficients(&*[(1-m*x^m)^20:m in [1..40]])[1..40] where x is PolynomialRing(Integers()).1; // G. C. Greubel, Jul 18 2018
CROSSREFS
KEYWORD
sign
AUTHOR
STATUS
approved