Column 2 of triangle A152400.

Terms

a(0) =1a(1) =3a(2) =15a(3) =99a(4) =794a(5) =7414a(6) =78507a(7) =926026a(8) =12010188a(9) =169580899a(10) =2586371577a(11) =42336163519a(12) =739814864633