a(n) = Sum_{k=0..n} binomial(3*n,k) * binomial(4*n-k-1,n-k).

A370098

a(n) = Sum_{k=0..n} binomial(3*n,k) * binomial(4*n-k-1,n-k).

Terms

    a(0) =1a(1) =6a(2) =72a(3) =978a(4) =14016a(5) =207006a(6) =3116952a(7) =47568618a(8) =733189632a(9) =11387193846a(10) =177923724072

External references