a(n) = Product_{k=0..n} (3*k)!/(n+k)!.

A266091

a(n) = Product_{k=0..n} (3*k)!/(n+k)!.

Terms

    a(0) =1a(1) =3a(2) =15a(3) =126a(4) =1782a(5) =42471a(6) =1706562a(7) =115640460a(8) =13216815036

External references