a(n) = Sum_{k=0..n} binomial(3*n+2,5*k).

Terms

a(0) =1a(1) =2a(2) =57a(3) =474a(4) =3004a(5) =25773a(6) =215766a(7) =1669801a(8) =13333932a(9) =107746282a(10) =859595529a(11) =6863694378a(12) =54986385093a(13) =439924466026