a(n) = (A005867(n+1) - A000165(n))/96.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =20a(6) =480a(7) =10560a(8) =272640a(9) =8709120a(10) =280627200a(11) =10644480000a(12) =439404134400