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 A074689 #6 Oct 15 2015 10:55:23 %S A074689 0,1,3,2,8,7,4,5,6,22,21,17,18,20,9,10,11,12,13,14,15,19,16,64,63,58, %T A074689 59,62,45,46,48,49,50,54,55,61,57,23,24,25,26,27,28,29,30,31,32,33,34, %U A074689 35,36,37,38,39,40,41,51,52,60,56,42,43,44,47,53,196,195,189,190,194 %N A074689 Permutation of natural numbers induced by the Catalan bijection gmA074689! acting on the parenthesizations encoded by A014486/A063171. %H A074689 A. Karttunen, <a href="http://www.iki.fi/~kartturi/matikka/Nekomorphisms/gatomorf.htm">Gatomorphisms</a> (with the complete Scheme source) %H A074689 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A074689 (Scheme function implementing this automorphism on list-structures:) %o A074689 (define (gmA074689! s) (cond ((pair? s) (gmrobr! s) (gmA074689! (car s)))) s) %Y A074689 Inverse of A074690. a(n) = A057163(A074685(A057163(n))). Cf. A074681-A074688. Occurs in A073200. %K A074689 nonn %O A074689 0,3 %A A074689 _Antti Karttunen_, Sep 11 2002