G.f. satisfies A(x) = 1 + x^2 + x*A(x)^4.

Terms

a(0) =1a(1) =1a(2) =5a(3) =26a(4) =168a(5) =1195a(6) =8988a(7) =70318a(8) =566388a(9) =4665221a(10) =39113732a(11) =332691758a(12) =2863778072a(13) =24900264326a(14) =218372530380