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

Terms

a(0) =1a(1) =0a(2) =3a(3) =-11a(4) =25a(5) =-59a(6) =721a(7) =-10919a(8) =60481a(9) =-15119a(10) =3628801a(11) =-93471839a(12) =479001601a(13) =-8648639a(14) =134399865601