a(n) = A163085(n)/n!.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =18a(6) =60a(7) =1200a(8) =10500a(9) =735000a(10) =18522000a(11) =4667544000a(12) =359400888000