Column 3 of triangle A107880.

Terms

a(0) =1a(1) =2a(2) =9a(3) =61a(4) =550a(5) =6195a(6) =83837a(7) =1326923a(8) =24078588a(9) =493309850a(10) =11271757335a(11) =284379843234