a(n) = -Sum_{d|n} (-n)^d.

Terms

a(0) =1a(1) =-2a(2) =30a(3) =-268a(4) =3130a(5) =-46470a(6) =823550a(7) =-16781368a(8) =387421227a(9) =-9999900090a(10) =285311670622