OFFSET
0,2
FORMULA
a(0) = 1; a(n) = Sum_{k=1..n} ((-1)^(k-1) * (k-1)! + 1) * binomial(n,k) * a(n-k).
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(1/(2-exp(x)-log(1+x))))
(PARI) a(n) = if(n==0, 1, sum(k=1, n, ((-1)^(k-1)*(k-1)!+1)*binomial(n, k)*a(n-k)));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 10 2022
STATUS
approved