a(n) = (n+1)^3*(3+n)!/6.

A154306

a(n) = (n+1)^3*(3+n)!/6.

Terms

    a(0) =1a(1) =32a(2) =540a(3) =7680a(4) =105000a(5) =1451520a(6) =20744640a(7) =309657600a(8) =4849891200a(9) =79833600000

External references