Column 0 of triangle A135880.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =25a(5) =138a(6) =970a(7) =8390a(8) =86796a(9) =1049546a(10) =14563135a(11) =228448504a(12) =4002300038a(13) =77523038603