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

Terms

a(0) =0a(1) =216a(2) =5184a(3) =77760a(4) =933120a(5) =9797760a(6) =94058496a(7) =846526464a(8) =7255941120a(9) =59861514240a(10) =478892113920