G.f. A(x) satisfies A(x) = 1 + x*(1-x^2)^2*A(x)^3.

Terms

a(0) =1a(1) =1a(2) =3a(3) =10a(4) =43a(5) =202a(6) =1006a(7) =5202a(8) =27655a(9) =150192a(10) =829678a(11) =4647342a(12) =26334058a(13) =150685297a(14) =869468278a(15) =5053346800a(16) =29556408331a(17) =173838629041