Expansion of g.f. (1 + x - 2*x^2 - x^3)/(1/2 - 2*x^2 + x^4).

Terms

a(0) =2a(1) =2a(2) =4a(3) =6a(4) =12a(5) =20a(6) =40a(7) =68a(8) =136a(9) =232a(10) =464a(11) =792a(12) =1584a(13) =2704a(14) =5408a(15) =9232a(16) =18464a(17) =31520a(18) =63040a(19) =107616a(20) =215232a(21) =367424a(22) =734848a(23) =1254464a(24) =2508928a(25) =4283008a(26) =8566016a(27) =14623104a(28) =29246208a(29) =49926400