OFFSET
0,9
FORMULA
a(0)=1; a(n) = Sum_{k=0..floor((n-4)/3)} binomial(n-1,3*k+3) * a(n-3*k-4).
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(sum(k=0, N\3, x^(3*k+4)/(3*k+4)!))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Sep 22 2023
STATUS
approved