a(n) = n!*tetranacci(n+3).

Terms

a(0) =1a(1) =1a(2) =4a(3) =24a(4) =192a(5) =1800a(6) =20880a(7) =282240a(8) =4354560a(9) =75479040a(10) =1455148800a(11) =30855686400a(12) =713712384000