OFFSET
0,2
LINKS
Winston de Greef, Table of n, a(n) for n = 0..907
FORMULA
a(n) = Sum_{k=0..n} (-9)^k * binomial(-1/3,k) * binomial(n+3*k-1,n-k).
a(0) = 1; a(n) = (3/n) * Sum_{k=0..n-1} (n+2*k) * binomial(n+2-k,3) * a(k).
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(1/(1-9*x/(1-x)^4)^(1/3))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 28 2023
STATUS
approved