Column 2 of triangle A112911.

Terms

a(0) =1a(1) =3a(2) =15a(3) =96a(4) =729a(5) =6327a(6) =61380a(7) =655944a(8) =7642557a(9) =96338925a(10) =1306003803a(11) =18947038404a(12) =292956751236