OFFSET
0,2
FORMULA
a(n) = n! * Sum_{k=0..floor(n/3)} (k+2)^(n-3*k)/(n-3*k)!.
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(2*x)/(1-x^3*exp(x))))
(PARI) a(n) = n!*sum(k=0, n\3, (k+2)^(n-3*k)/(n-3*k)!);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Aug 21 2024
STATUS
approved