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 A130372 #5 Mar 31 2012 13:21:14 %S A130372 0,1,2,3,4,5,6,8,7,9,10,11,12,13,14,15,16,22,21,19,17,18,20,23,24,25, %T A130372 27,26,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,64,63,47,58, %U A130372 59,62,51,52,53,46,45,56,48,49,50,60,54,55,57,61,65,66,67,68,69,70,71 %N A130372 Signature permutation of a Catalan automorphism: apply *A074686 to the last subtree, if the root degree (A057515(n)) is odd. %H A130372 A. Karttunen, <a href="/A130372/b130372.txt">Table of n, a(n) for n = 0..2055</a> %H A130372 <a href="/index/Per#IntegerPermutationCatAuto">Index entries for signature-permutations of Catalan automorphisms</a> %o A130372 (Destructive Scheme implementation of this automorphism, which acts on S-expressions, i.e. list-structures:) %o A130372 (define (*A130372! s) (if (odd? (length s)) (*A074686! (car (last-pair s)))) s) %Y A130372 Inverse: A130371. a(n) = A074686(A130369(n)) = A074686(A130376(A074685(n))) = A130370(A130376(A130369(n))). %K A130372 nonn %O A130372 0,3 %A A130372 _Antti Karttunen_, Jun 05 2007