OFFSET
0,2
COMMENTS
This sequence is obtained from the generalized Euler transform in A266964 by taking f(n) = 4, g(n) = n. - Seiichi Manyama, Dec 29 2017
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..1000
FORMULA
G.f.: exp(4*Sum_{j>=1} Sum_{k>=1} k^j*x^(j*k)/j). - Ilya Gutkovskiy, Feb 07 2018
MATHEMATICA
With[{nmax = 50}, CoefficientList[Series[Product[(1 - k*q^k)^-4, {k, 1, nmax}], {q, 0, nmax}], q]] (* G. C. Greubel, Jul 25 2018 *)
PROG
(PARI) m=50; q='q+O('q^m); Vec(prod(n=1, m, (1-n*q^n)^-4)) \\ G. C. Greubel, Jul 25 2018
(Magma) n:=50; R<x>:=PowerSeriesRing(Integers(), n); Coefficients(R!(&*[(1/(1-m*x^m))^4:m in [1..n]])); // G. C. Greubel, Jul 25 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved