Column 0 of triangle A152391.

Terms

a(0) =1a(1) =1a(2) =4a(3) =18a(4) =96a(5) =580a(6) =3852a(7) =27678a(8) =212224a(9) =1722312a(10) =14685140a(11) =130892938a(12) =1214128032a(13) =11680325020a(14) =116190588780