G.f. A(x) = 1 + 4*x*A(x)^(1/2); A(x) = 1 + 8*x^2 + 4*x*sqrt(1 + 4*x^2).

Terms

a(0) =1a(1) =4a(2) =8a(3) =8a(4) =0a(5) =-8a(6) =0a(7) =16a(8) =0a(9) =-40a(10) =0a(11) =112a(12) =0a(13) =-336a(14) =0a(15) =1056a(16) =0a(17) =-3432a(18) =0a(19) =11440a(20) =0a(21) =-38896a(22) =0a(23) =134368a(24) =0a(25) =-470288a(26) =0a(27) =1664096a(28) =0a(29) =-5943200