Column 0 of triangle A107884.

Terms

a(0) =1a(1) =3a(2) =6a(3) =16a(4) =63a(5) =351a(6) =2609a(7) =24636a(8) =284631a(9) =3909926a(10) =62459868a(11) =1140206571a(12) =23453446130a(13) =537365482536