%I #3 Mar 30 2012 18:36:43
%S 1,4,12,44,236,2028,29164,719340,30943724,2350770668,318680099308,
%T 77793540073964,34472347123476972,27928291976711924204,
%U 41631598900551078537708,114829789064202679162399212
%N Column 2 of triangle A098542, which shifts left and up under the matrix square.
%C Related to A002449, the number of different types of binary trees of height n.
%F G.f.: A(x) = x*(1+x)/(1-x)*(G002449(x)-1), where G002449(x) is g.f. of A002449.
%Y Cf. A002449, A098542, A098544.
%K nonn
%O 2,2
%A _Paul D. Hanna_, Sep 16 2004