a(n) = (4n^2+2n+1) * n!.

Terms

a(0) =1a(1) =7a(2) =42a(3) =258a(4) =1752a(5) =13320a(6) =113040a(7) =1063440a(8) =11007360a(9) =124467840a(10) =1527724800a(11) =20237817600a(12) =287879961600