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 A126305 #4 Mar 31 2012 13:21:13 %S A126305 1,1,1,2,1,2,2,3,2,1,2,2,3,2,2,3,3,4,3,2,3,2,3,1,2,2,3,2,2,3,3,4,3,2, %T A126305 3,2,3,2,3,3,4,3,3,4,4,5,4,3,4,3,4,2,3,3,4,3,2,3,2,3,3,4,3,4,3,1,2,2, %U A126305 3,2,2,3,3,4,3,2,3,2,3,2,3,3,4,3,3,4,4,5,4,3,4,3,4,2,3,3,4,3,2,3,2,3 %N A126305 a(n) = number of nodes with even distance to the root in the n-th plane general tree encoded by A014486(n). The root node itself is also included. %Y A126305 a(n) = A126304(n)+1 = A072643(n)-A126303(n). a(n) = A057514(A125982(n)) for all n >=1. %K A126305 nonn %O A126305 0,4 %A A126305 _Antti Karttunen_, Jan 02 2007