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 A057118 #5 May 01 2014 02:48:24 %S A057118 0,1,2,3,4,5,8,6,7,9,10,13,11,12,19,20,21,14,15,22,18,16,17,23,24,27, %T A057118 25,26,33,34,35,28,29,36,32,30,31,51,52,55,53,54,58,59,56,37,38,57,41, %U A057118 39,40,62,63,64,47,48,60,49,42,43,61,50,46,44,45,65,66,69,67,68,75,76 %N A057118 Permutation of natural numbers induced by the automorphism df->bf (switch from the Depth First to the Breadth First coding for the binary trees) acting on the planar binary trees encoded by A014486. %H A057118 A. Karttunen, <a href="http://www.iki.fi/~kartturi/matikka/Nekomorphisms/gatomorf.htm">Gatomorphisms</a> (Includes the complete Scheme program for computing this sequence) %H A057118 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %Y A057118 Restriction of the automorphism A072089 to the plane binary trees. Being self-embeddable, this allows us also to form the permutation A070041. Inverse permutation: A057117. %K A057118 nonn %O A057118 0,3 %A A057118 _Antti Karttunen_, Aug 11 2000