Column 1 of triangle A112911.

Terms

a(0) =1a(1) =2a(2) =8a(3) =44a(4) =298a(5) =2358a(6) =21154a(7) =211100a(8) =2313030a(9) =27566654a(10) =354806116a(11) =4903884712a(12) =72444584732