OFFSET
0,4
FORMULA
E.g.f.: (1/x) * Series_Reversion( x*exp(x*(1 - exp(x^2))) ).
a(n) = n! * Sum_{k=0..floor(n/2)} (n+1)^(n-2*k-1) * Stirling2(k,n-2*k)/k!.
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(serreverse(x*exp(x*(1-exp(x^2))))/x))
(PARI) a(n) = n!*sum(k=0, n\2, (n+1)^(n-2*k-1)*stirling(k, n-2*k, 2)/k!);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Sep 21 2024
STATUS
approved