a(n) = Product_{k=0..n-1} (n+3*k+1).

A384256

a(n) = Product_{k=0..n-1} (n+3*k+1).

Terms

    a(0) =1a(1) =2a(2) =18a(3) =280a(4) =6160a(5) =174960a(6) =6086080a(7) =250490240a(8) =11904278400a(9) =641472832000

External references