a(n) = (n^3 + n)*6^n.

Terms

a(0) =12a(1) =360a(2) =6480a(3) =88128a(4) =1010880a(5) =10357632a(6) =97977600a(7) =873400320a(8) =7437339648a(9) =61070837760a(10) =486873649152