a(n) = (n-1)! * Sum_{d|n} (-1)^(d+1) / (d-1)!.

Terms

a(0) =1a(1) =0a(2) =3a(3) =-1a(4) =25a(5) =59a(6) =721a(7) =-841a(8) =60481a(9) =15119a(10) =3628801a(11) =12972959a(12) =479001601a(13) =8648639a(14) =134399865601a(15) =-218205187201