a(0)=1, a(n) = n*(a(n-1) - 1) for n>0.

Terms

a(0) =1a(1) =0a(2) =-2a(3) =-9a(4) =-40a(5) =-205a(6) =-1236a(7) =-8659a(8) =-69280a(9) =-623529a(10) =-6235300a(11) =-68588311a(12) =-823059744a(13) =-10699776685a(14) =-149796873604