G.f. A(x) satisfies: A(x) = x + x^2 * exp( Sum_{k>=1} (-1)^(k+1) * A(x^k)^2 / (k*x^k) ).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =5a(5) =10a(6) =28a(7) =70a(8) =190a(9) =517a(10) =1441a(11) =4057a(12) =11572a(13) =33294a(14) =96620a(15) =282319a(16) =830178a(17) =2454384a(18) =7292106a(19) =21759413a(20) =65185967a(21) =195976025a(22) =591097127a(23) =1788122219a(24) =5423917828a(25) =16493458475a(26) =50270190728a(27) =153544874713a(28) =469916030995