OFFSET
0,3
FORMULA
a(n) = Sum_{k=0..floor(n/2)} (-9)^k * binomial(-1/3,k) * binomial(n+k,n-2*k).
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(1/((1-x)^3-9*x^2)^(1/3))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Oct 04 2024
STATUS
approved