3rd column of A145142.

Terms

a(0) =1a(1) =6a(2) =35a(3) =225a(4) =2464a(5) =29932a(6) =375164a(7) =4877100a(8) =73016856a(9) =1229669496a(10) =22393143552a(11) =430226343456