a(n) = 6^n * n*(n+1).

Terms

a(0) =0a(1) =12a(2) =216a(3) =2592a(4) =25920a(5) =233280a(6) =1959552a(7) =15676416a(8) =120932352a(9) =906992640a(10) =6651279360a(11) =47889211392a(12) =339578044416