a(n) = n^2*6^n.

Terms

a(0) =0a(1) =6a(2) =144a(3) =1944a(4) =20736a(5) =194400a(6) =1679616a(7) =13716864a(8) =107495424a(9) =816293376a(10) =6046617600a(11) =43898443776a(12) =313456656384