OFFSET
0,2
FORMULA
a(n) = (1/(n+1)) * Sum_{k=0..n} binomial(n+k,k) * binomial(5*n+3*k+3,n-k).
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serreverse(x*((1-x)^4-x))/x)
(PARI) a(n) = sum(k=0, n, binomial(n+k, k)*binomial(5*n+3*k+3, n-k))/(n+1);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jan 16 2024
STATUS
approved