G.f. satisfies: A(x) = Sum_{n>=0} x^n*(1 + x*A(x)^n)^n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =11a(5) =35a(6) =123a(7) =462a(8) =1829a(9) =7558a(10) =32380a(11) =143102a(12) =649999a(13) =3026171a(14) =14411412a(15) =70095713a(16) =347817785a(17) =1759198500a(18) =9063638685a(19) =47545501777a(20) =253854457415