OFFSET
0,5
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..449
FORMULA
a(0) = 1; a(n) = (n-1)! * Sum_{k=4..n} k/(k-3) * a(n-k)/(n-k)!.
a(n) = n! * Sum_{k=0..floor(n/4)} |Stirling1(n-3*k,k)|/(n-3*k)!.
a(n) ~ sqrt(2*Pi) * n^(n + 1/2) / exp(n). - Vaclav Kotesovec, May 04 2022
MATHEMATICA
With[{nn=30}, CoefficientList[Series[(1-x)^-x^3, {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Jun 20 2024 *)
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace((1-x)^(-x^3)))
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(-x^3*log(1-x))))
(PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=(i-1)!*sum(j=4, i, j/(j-3)*v[i-j+1]/(i-j)!)); v;
(PARI) a(n) = n!*sum(k=0, n\4, abs(stirling(n-3*k, k, 1))/(n-3*k)!);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, May 01 2022
STATUS
approved