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 A262430 #7 Sep 22 2015 13:28:29 %S A262430 1,0,1,1,1,2,3,6,12,25,54,120,278,657,1586,3885,9676,24350,61974, %T A262430 159066,411637,1072477,2812147,7414611,19650656,52319946,139898593, %U A262430 375536661,1011726481,2734793731,7415449225,20165442393,54986240994,150314506170,411889913114,1131183374539,3113153283443,8584839296108,23718157486109,65645273392938,181995130879151,505374042479921,1405493247220915,3914493122094481,10917513971606377,30489195524251154,85254349619909519,238677545463592954,668973050139380099,1877097093098685409,5272616851780131627 %N A262430 Number of trees on n vertices with an even number of leaves. %C A262430 For n>=0, a(n) + A262431(n) = A000055(n). %C A262430 For n>=2, a(n) - A262431(n) = A262395(n). %F A262430 G.f.: (A(x,1)+A(x,-1))/2, where A(x,y) is g.f. for A055290. %Y A262430 Cf. A000055, A055290, A055277, A262431. %K A262430 nonn %O A262430 0,6 %A A262430 _Max Alekseyev_, Sep 22 2015