a(n) = floor(exp(11/24)*n!).

Terms

a(0) =1a(1) =3a(2) =9a(3) =37a(4) =189a(5) =1138a(6) =7970a(7) =63763a(8) =573871a(9) =5738715a(10) =63125866a(11) =757510403a(12) =9847635243a(13) =137866893402