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

Terms

a(0) =0a(1) =0a(2) =72a(3) =1296a(4) =15552a(5) =155520a(6) =1399680a(7) =11757312a(8) =94058496a(9) =725594112a(10) =5441955840a(11) =39907676160a(12) =287335268352