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 A073209 #7 Oct 15 2015 10:57:13 %S A073209 0,1,2,3,4,7,5,6,8,9,10,17,16,18,11,21,12,14,20,13,15,19,22,23,24,25, %T A073209 26,27,45,46,44,42,49,48,43,47,50,28,29,58,56,63,30,57,31,37,38,32,54, %U A073209 53,62,33,59,34,39,61,35,40,51,55,36,41,52,60,64,65,66,67,68,69,70,71 %N A073209 Permutation of natural numbers induced by the Catalan bijection gmA073209 acting on the parenthesizations as ordered by A014486. %C A073209 Is there an equivalent Catalan bijection in A073200? %H A073209 A. Karttunen, <a href="http://www.iki.fi/~kartturi/matikka/Nekomorphisms/gatomorf.htm">Gatomorphisms</a> (with the complete Scheme source) %H A073209 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A073209 (Scheme function implementing this automorphism on list-structures:) %o A073209 (define (gmA073209 s) (cond ((pair? s) (gmA072796! s) (gmA073209 (car s)) (gmA072797! s) (gmA073209 (car s)))) s) %Y A073209 Inverse permutation: A073210. The car/cdr-flipped conjugate of A073198, i.e. A073209(n) = A057163(A073198(A057163(n))). Cf. also A073205-A073208. %Y A073209 The scheme functions gma072796! and gma072797! referred to below are given in A072796 and A072797. %K A073209 nonn %O A073209 0,3 %A A073209 _Antti Karttunen_, Jun 25 2002