Column 2 of triangle A105620.

Terms

a(0) =1a(1) =-3a(2) =-7a(3) =-39a(4) =-315a(5) =-3243a(6) =-40167a(7) =-579159a(8) =-9514395a(9) =-175345083a(10) =-3582404487a(11) =-80368306119