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 A127289 #8 Jul 24 2025 19:11:11 %S A127289 0,1,3,2,6,8,7,5,4,15,20,14,19,21,18,22,16,11,13,17,12,10,9,39,53,41, %T A127289 55,59,40,54,38,52,57,37,51,56,58,47,60,49,62,64,48,61,43,29,34,42,28, %U A127289 33,35,50,63,46,32,36,44,30,25,27,45,31,26,24,23,113,155,118,160,173 %N A127289 Signature-permutation of a Catalan automorphism: composition of A127291 and A057164. %C A127289 This is otherwise like A127291, but uses A127285 instead of A127287 as a "picker permutation" for the function "tau", which can be found in the entry A127291. A014486->parenthesization is given in A014486. This permutation contains some exceptionally large cycles, see A127297. %H A127289 A. Karttunen, <a href="/A127289/b127289.txt">Table of n, a(n) for n = 0..2055</a> %H A127289 <a href="/index/Per#IntegerPermutationCatAuto">Index entries for signature-permutations of Catalan automorphisms</a> %o A127289 (Scheme) (define (A127289 n) (tau (A014486->parenthesization (A014486 n)) *A127285!)) %Y A127289 Inverse: A127290. a(n) = A127291(A057164(n)) = A057164(A127299(n)). The number of cycles, maximum cycle sizes and LCM's of all cycle sizes in range [A014137(n-1)..A014138(n-1)] of this permutation are given by A127296, A127297 and A127298. %K A127289 nonn %O A127289 0,3 %A A127289 _Antti Karttunen_, Jan 16 2007