Expansion of 1/(g * (2-g))^2, where g = 1+x*g^2 is the g.f. of A000108.

Terms

a(0) =1a(1) =0a(2) =2a(3) =8a(4) =31a(5) =120a(6) =466a(7) =1816a(8) =7099a(9) =27824a(10) =109294a(11) =430104a(12) =1695222a(13) =6690448a(14) =26434916a(15) =104551024a(16) =413858131a(17) =1639464544a(18) =6498928726a(19) =25777365784a(20) =102297477346a(21) =406160315344