OFFSET
0,3
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..181
FORMULA
a(0) = 1, a(n) = -Sum_{k=1..n} (k!)^3 * a(n-k).
a(n) ~ -(n!)^3 * (1 - 2/n^3 - 13/n^6 - 39/n^7 - 78/n^8 - 518/n^9 - 3687/n^10 - ...). - Vaclav Kotesovec, Dec 08 2020
MATHEMATICA
a[n_] := -Sum[(k!)^3*a[n - k], {k, n}]; a[0] = 1; Array[a, 15, 0] (* Robert G. Wilson v, Jul 15 2018 *)
nmax = 20; CoefficientList[Series[1/Sum[k!^3 * x^k, {k, 0, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Dec 08 2020 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Jul 15 2018
STATUS
approved