a(n) = floor(exp(17/24)*n!).

Terms

a(0) =2a(1) =4a(2) =12a(3) =48a(4) =243a(5) =1462a(6) =10234a(7) =81873a(8) =736865a(9) =7368656a(10) =81055217a(11) =972662611a(12) =12644613946a(13) =177024595248