a(n) = Product_{k=0..n-1} (3*n+k-2).

A384262

a(n) = Product_{k=0..n-1} (3*n+k-2).

Terms

    a(0) =1a(1) =1a(2) =20a(3) =504a(4) =17160a(5) =742560a(6) =39070080a(7) =2422728000a(8) =173059286400

External references