OFFSET
0,2
FORMULA
a(n) = n! * Sum_{k=0..floor(n/2)} binomial(n+1+k,n-2*k)/k!.
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(x^2/(1-x)^3)/(1-x)^2))
(PARI) a(n) = n!*sum(k=0, n\2, binomial(n+1+k, n-2*k)/k!);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Aug 06 2024
STATUS
approved