Column 2 of triangle A132845.

Terms

a(0) =1a(1) =3a(2) =18a(3) =95a(4) =693a(5) =4893a(6) =40506a(7) =338277a(8) =3110310a(9) =29270549a(10) =294099936a(11) =3036380607a(12) =32913111931a(13) =366636699553