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 A130920 #5 Mar 31 2012 13:21:16 %S A130920 0,1,2,3,4,6,5,7,8,9,14,10,16,19,11,15,12,17,18,13,20,21,22,23,37,24, %T A130920 42,51,25,38,26,44,47,27,53,56,60,28,39,29,43,52,30,40,31,45,48,32,54, %U A130920 49,50,33,41,34,46,55,35,57,58,62,36,61,59,63,64,65,107,66,121,149,67 %N A130920 Signature permutation of a Catalan automorphism: DEEPEN-transform of automorphism *A057512. %C A130920 *A130920 = DEEPEN(*A057512) = NEPEED(*A057512) = DEEPEN(DEEPEN(*A057510)) = NEPEED(NEPEED(*A057510)). See A122283, A122284 for the definitions of DEEPEN and NEPEED transforms. %H A130920 A. Karttunen, <a href="/A130920/b130920.txt">Table of n, a(n) for n = 0..2055</a> %H A130920 <a href="/index/Per#IntegerPermutationCatAuto">Index entries for signature-permutations of Catalan automorphisms</a> %Y A130920 Inverse: A130919. A122351(n) = A083927(A130920(A057123(n))). %K A130920 nonn %O A130920 0,3 %A A130920 _Antti Karttunen_, Jun 11 2007