Column 2 of triangle A134090.

Terms

a(0) =1a(1) =3a(2) =18a(3) =110a(4) =780a(5) =6167a(6) =53494a(7) =504030a(8) =5112090a(9) =55411697a(10) =638154165a(11) =7770348170a(12) =99618149267