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 A085171 #8 Oct 15 2015 10:55:24 %S A085171 0,1,2,3,4,6,7,5,8,9,11,14,16,19,17,20,12,10,15,21,18,13,22,23,25,28, %T A085171 30,33,37,39,42,44,53,51,56,47,60,45,48,54,57,61,31,34,26,24,29,40,38, %U A085171 43,52,58,62,49,46,55,35,32,27,41,63,59,50,36,64,65,67,70,72,75 %N A085171 Permutation of natural numbers induced by the Catalan bijection gma085171 acting on symbolless S-expressions encoded by A014486/A063171. %H A085171 A. Karttunen, <a href="http://www.iki.fi/~kartturi/matikka/Nekomorphisms/gatomorf.htm">Gatomorphisms</a> (With the complete Scheme source) %H A085171 <a href="/index/Per#IntegerPermutationCatAuto">Index entries for signature-permutations induced by Catalan automorphisms</a> %o A085171 (Scheme function implementing this automorphism on list-structures:) %o A085171 (define (gma085171! s) (cond ((null? s) s) (else (app-to-xrt! (gma085171! (car s)) (append! (map gma085171! (cdr s)) (list (list))))))) %Y A085171 Inverse: A085172. Cf. also A085163, A085164, A085203. %K A085171 nonn %O A085171 0,3 %A A085171 _Antti Karttunen_, Jun 23 2003