Partial sums of A156832.

Terms

a(0) =1a(1) =2a(2) =3a(3) =6a(4) =30a(5) =120a(6) =840a(7) =3360a(8) =13440a(9) =134400a(10) =739200a(11) =6652800a(12) =86486400a(13) =778377600a(14) =16345929600a(15) =81729648000