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 A082356 #14 Mar 31 2012 14:02:27 %S A082356 0,1,2,3,4,5,7,8,6,9,10,12,13,11,17,18,21,22,20,14,15,16,19,23,24,26, %T A082356 27,25,31,32,35,36,34,28,29,30,33,45,46,49,50,48,58,59,63,64,62,54,55, %U A082356 57,61,37,38,40,41,39,42,43,44,47,51,52,56,60,53,65,66,68,69,67 %N A082356 Permutation of natural numbers induced by Catalan Automorphism *A082356 acting on the parenthesizations encoded by A014486/A063171. %C A082356 This bijection maps between the "standard" ordering of binary trees as encoded by A014486 and "variant B quaternary encoding" as explained in the sequence A085184. %H A082356 A. Karttunen, <a href="http://oeis.org/wiki/Catalan_Automorphisms">Catalan Automorphisms</a> %H A082356 <a href="/index/Per#IntegerPermutationCatAuto">Index entries for signature-permutations induced by Catalan automorphisms</a> %o A082356 (Scheme function implementing this automorphism on S-expressions/list-structures:) %o A082356 (define (*A082356! s) (cond ((pair? s) (*A082352! s) (*A082356! (car s)) (*A082356! (cdr s)))) s) %Y A082356 Inverse of A082355. a(n) = A057163(A082358(n)). a(n) = A082364(A082853(n))+A082852(n). Cf. also A082351-A082352, A082357-A082358. %Y A082356 Differs from A057117 first time at n=56: a(56)=42, while A057117(56)=44. %K A082356 nonn %O A082356 0,3 %A A082356 _Antti Karttunen_, Apr 17 2003