G.f. satisfies A(x) = x + x*A(A(A(x))).

Terms

a(0) =1a(1) =1a(2) =3a(3) =15a(4) =99a(5) =781a(6) =7001a(7) =69253a(8) =742071a(9) =8506775a(10) =103411463a(11) =1324477033a(12) =17785238513a(13) =249432247233