G.f. satisfies A(x) = 1 + x*A(x)^2 + x^3*A(x)^5.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =21a(5) =78a(6) =302a(7) =1210a(8) =4979a(9) =20913a(10) =89284a(11) =386308a(12) =1690221a(13) =7465594a(14) =33243970a(15) =149080710a(16) =672682035a(17) =3051859515a(18) =13913105076a(19) =63704186436a(20) =292825392338