a(n) = A203418(n+1)/A203418(n).

Terms

a(0) =2a(1) =8a(2) =15a(3) =48a(4) =1152a(5) =19200a(6) =62370a(7) =322560a(8) =17418240a(9) =567705600a(10) =2481078600a(11) =16907304960