%I #12 Aug 08 2019 21:06:39
%S 1,1,1,2,4,10,28,86,286,1019,3857,15418,64782,285041,1309355,6263085,
%T 31127475,160432093,856039863,4721638083,26883787141,157812750656,
%U 953995201996,5932516347277,37913110456751,248768719522450,1674488577654500,11553041105489900
%N Shifts left 2 places under COMPOSE transform.
%H N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>
%F G.f. A(x) satisfies: A(x) = x + x^2 * (1 + A(A(x))). - _Ilya Gutkovskiy_, May 10 2019
%t Nest[x + x^2 + x^2 (# /. x -> #) &, O[x], 20][[3]] (* _Vladimir Reshetnikov_, Aug 08 2019 *)
%Y Cf. A030266.
%K nonn,eigen
%O 1,4
%A _Christian G. Bower_