a(n) = (4*n-1)! / (n! * n! * n! * (n-1)! * 3!).

A082368

a(n) = (4*n-1)! / (n! * n! * n! * (n-1)! * 3!).

Terms

    a(0) =1a(1) =105a(2) =15400a(3) =2627625a(4) =488864376a(5) =96197645544

External references