Column 1 of triangle A127126.

Terms

a(0) =1a(1) =2a(2) =9a(3) =54a(4) =412a(5) =3834a(6) =42131a(7) =533558a(8) =7645065a(9) =122177706a(10) =2153221318a(11) =41464853266a(12) =865908079369