OFFSET
0,3
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..180
FORMULA
a(n) = (n!)^3 * [x^n] 1 / (1 - Sum_{k>=1} x^k / (k!)^3).
MATHEMATICA
a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, k]^3 a[k], {k, 0, n - 1}]; Table[a[n], {n, 0, 14}]
nmax = 14; CoefficientList[Series[1/(1 - Sum[x^k/(k!)^3, {k, 1, nmax}]), {x, 0, nmax}], x] Range[0, nmax]!^3
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jul 11 2020
STATUS
approved