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Column 2 of triangle A098542, which shifts left and up under the matrix square.
2

%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