a(n) = n!*(n+6)! / 6!.

A010795

a(n) = n!*(n+6)! / 6!.

Terms

    a(0) =1a(1) =7a(2) =112a(3) =3024a(4) =120960a(5) =6652800a(6) =479001600a(7) =43589145600

External references