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

Terms

a(0) =1a(1) =1a(2) =4a(3) =9a(4) =35a(5) =104a(6) =376a(7) =1321a(8) =4960a(9) =18667a(10) =72220a(11) =282368a(12) =1119791a(13) =4481428a(14) =18097960a(15) =73612825a(16) =301377323a(17) =1240776848a(18) =5133985196a(19) =21337546123a(20) =89037498752a(21) =372879415520