G.f. satisfies: A(x) = x + A( A(x)^2/(1 + A(x)^2) ).

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =14a(5) =43a(6) =140a(7) =475a(8) =1660a(9) =5932a(10) =21570a(11) =79541a(12) =296732a(13) =1117827a(14) =4246248a(15) =16246794a(16) =62555600a(17) =242201234a(18) =942384808a(19) =3682943857a(20) =14450545764a(21) =56902437222a(22) =224798143444a(23) =890730315852