This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A038056 #20 May 02 2020 15:45:59 %S A038056 2,3,6,18,54,189,700,2778,11486,49377,217936,984818,4533004,21198962, %T A038056 100471862,481754806,2333465628,11404047817,56177574628,278710061814, %U A038056 1391617108600,6988781174376,35283390923324,178990052273558,912019786448570,4665994686718118 %N A038056 Number of trees with n 2-colored nodes. %H A038056 Alois P. Heinz, <a href="/A038056/b038056.txt">Table of n, a(n) for n = 1..1000</a> %H A038056 <a href="/index/Tra#trees">Index entries for sequences related to trees</a> %F A038056 G.f.: B(x) - B^2(x)/2 + B(x^2)/2, where B(x) is g.f. for A038055. %Y A038056 Cf. A000055, A038055-A038062. Row sums of A294783. %K A038056 nonn %O A038056 1,1 %A A038056 _Christian G. Bower_, Jan 04 1999