OFFSET
0,2
FORMULA
a(n) = Sum_{k=0..n} binomial(2*n+5*k+1,k) * binomial(3*n+3*k,n-k)/(2*n+5*k+1).
PROG
(PARI) a(n) = sum(k=0, n, binomial(2*n+5*k+1, k)*binomial(3*n+3*k, n-k)/(2*n+5*k+1));
CROSSREFS
KEYWORD
nonn,new
AUTHOR
Seiichi Manyama, Dec 19 2024
STATUS
approved