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 A106457 #5 Mar 31 2012 14:02:21 %S A106457 0,1,2,2,3,3,3,3,4,4,4,4,5,4,4,3,4,5,6,5,4,5,6,4,7,6,5,5,5,5,8,4,9,5, %T A106457 6,6,9,7,6,5,10,5,8,6,5,7,11,5,5,8,5,7,7,6,12,5,7,6,13,6,14,9,5,4,6, %U A106457 10,15,6,5,7,15,6,16,10,7,8,14,7,8,6,6,11,6,6,5,9,17,6,13,6,18,8,9,12 %N A106457 Number of edges in each rooted plane tree produced with the GF(2)[X] factorization unranking algorithm presented in A106456. %C A106457 Also the digital length of A106456(n)/2. Each value v occurs A000108(v) times. %H A106457 A. Karttunen, <a href="/A091247/a091247.scm.txt">Scheme-program for computing this sequence.</a> %Y A106457 a(n) = A075167(A106443(n)). Permutation of A072643. %K A106457 nonn %O A106457 1,3 %A A106457 _Antti Karttunen_, May 09 2005