Second column of triangle A014784.

Terms

a(0) =0a(1) =1a(2) =3a(3) =12a(4) =69a(5) =552a(6) =5901a(7) =81444a(8) =1411197a(9) =30006624a(10) =768410349a(11) =23329316316a(12) =828656935485