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 A123496 #7 Mar 31 2012 13:21:12 %S A123496 0,1,3,2,7,8,4,5,6,17,18,20,21,22,9,10,11,12,13,16,19,14,15,45,46,48, %T A123496 49,50,54,55,57,58,59,61,62,63,64,23,24,25,26,27,28,29,30,31,32,33,34, %U A123496 35,36,44,47,53,56,60,42,51,37,38,43,52,39,40,41,129,130,132,133,134 %N A123496 Signature permutation of a nonrecursive Catalan automorphism: row 65796 of table A089840. %H A123496 A. Karttunen, <a href="/A089840/a089840p.txt">Prolog-program which illustrates the construction of this and other similar nonrecursive Catalan automorphisms.</a> %H A123496 <a href="/index/Per#IntegerPermutationCatAuto">Index entries for signature-permutations of Catalan automorphisms</a> %o A123496 (Scheme function, destructive implementation of this automorphism acting on S-expressions:) (define (*A123496! s) (cond ((null? s) s) ((and (pair? (car s)) (pair? (caar s))) (*A074680! s) (*A069770! s)) (else (*A074680! s))) s) %Y A123496 Inverse: A123495. a(n) = A069770(A082352(n)). Row 65796 of A089840. Used to construct automorphism *A082358. Cf. A069770 and A074680. %K A123496 nonn %O A123496 0,3 %A A123496 _Antti Karttunen_, Oct 11 2006