Floor(exp(19/23) * n!).

Terms

a(0) =2a(1) =4a(2) =13a(3) =54a(4) =274a(5) =1644a(6) =11513a(7) =92105a(8) =828949a(9) =8289494a(10) =91184437a(11) =1094213253a(12) =14224772297a(13) =199146812169