OFFSET
0,4
FORMULA
a(n) = n! * Sum_{k=0..floor(n/2)} Stirling2(n-k,n-2*k)/(n-k)!.
MATHEMATICA
With[{nn=30}, CoefficientList[Series[Exp[(Exp[x^2]-1)/x], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Oct 19 2024 *)
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp((exp(x^2)-1)/x)))
(PARI) a(n) = n!*sum(k=0, n\2, stirling(n-k, n-2*k, 2)/(n-k)!);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Oct 22 2022
STATUS
approved