G.f. satisfies: A(x)^2 = A(x^2)^2 + 4*x.

Terms

a(0) =1a(1) =2a(2) =0a(3) =0a(4) =2a(5) =-4a(6) =8a(7) =-16a(8) =32a(9) =-56a(10) =88a(11) =-112a(12) =64a(13) =240a(14) =-1264a(15) =4064a(16) =-10814a(17) =25500a(18) =-54200a(19) =102832a(20) =-166020a(21) =190808a(22) =22304a(23) =-1058880a(24) =4412424a(25) =-13496544a(26) =35306480a(27) =-82326496a(28) =172081840a(29) =-315115328