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 A057504 #16 Jul 09 2025 03:55:33 %S A057504 0,1,3,2,7,6,8,5,4,17,16,18,15,14,20,19,21,12,11,22,13,10,9,45,44,46, %T A057504 43,42,48,47,49,40,39,50,41,38,37,54,53,55,52,51,57,56,58,31,30,59,32, %U A057504 29,28,61,60,62,34,33,63,35,26,25,64,36,27,24,23,129,128,130,127,126 %N A057504 Signature-permutation of the inverse of Deutsch's 1998 bijection on Dyck paths. %H A057504 Emeric Deutsch, <a href="https://doi.org/10.1016/S0012-365X(97)00097-6">A bijection on Dyck paths and its consequences</a>, Discrete Math., 179 (1998), 253-256. %H A057504 Antti Karttunen, <a href="/A089408/a089408.c.txt">C program which computes this sequence</a>. %H A057504 <a href="/index/Per#IntegerPermutationCatAuto">Index entries for signature-permutations of Catalan automorphisms</a> %o A057504 (Scheme implementation of this automorphism that acts on S-expressions, i.e., list-structures:) %o A057504 (DESTRUCTIVE IMPLEMENTATION:) (define (*A057504! s) (cond ((pair? s) (*A057502! s) (*A057504! (cdr s)))) s) %Y A057504 Inverse: A057503. Row 12 of A122286. %Y A057504 A080237(n) = A057515(a(n)) holds for all n. See comment at A057503. %K A057504 nonn %O A057504 0,3 %A A057504 _Antti Karttunen_, Sep 03 2000 %E A057504 Equivalence with Deutsch's 1998 bijection realized Dec 15 2006 and entry edited accordingly by _Antti Karttunen_, Jan 16 2007