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

Terms

a(0) =1a(1) =1a(2) =4a(3) =7a(4) =18a(5) =39a(6) =95a(7) =232a(8) =606a(9) =1663a(10) =4839a(11) =14807a(12) =47330a(13) =156611a(14) =532308a(15) =1846622a(16) =6507103a(17) =23210020a(18) =83590477a(19) =303425693a(20) =1108650850a(21) =4073443378a(22) =15039391464a(23) =55763147423a(24) =207543422052a(25) =775082175863