|
%I #20 May 02 2020 15:45:59
%S 2,3,6,18,54,189,700,2778,11486,49377,217936,984818,4533004,21198962,
%T 100471862,481754806,2333465628,11404047817,56177574628,278710061814,
%U 1391617108600,6988781174376,35283390923324,178990052273558,912019786448570,4665994686718118
%N Number of trees with n 2-colored nodes.
%H Alois P. Heinz, <a href="/A038056/b038056.txt">Table of n, a(n) for n = 1..1000</a>
%H <a href="/index/Tra#trees">Index entries for sequences related to trees</a>
%F G.f.: B(x) - B^2(x)/2 + B(x^2)/2, where B(x) is g.f. for A038055.
%Y Cf. A000055, A038055-A038062. Row sums of A294783.
%K nonn
%O 1,1
%A _Christian G. Bower_, Jan 04 1999
|
