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 A261293 #5 Aug 15 2015 03:30:55 %S A261293 0,1,2,3,4,5,6,7,8,9,10,11,15,20,25,21,30,31,35,41,40,12,45,51,50,13, %T A261293 115,61,60,14,81,71,32,165,92,43,103,16,54,91,114,17,65,101,125,18,76, %U A261293 111,126,19,121,22,26,70,131,87,36,141,46,42,151,52,56,62 %N A261293 a(n) = A065649(A065649(n)). %C A261293 Permutation of the nonnegatve integers with inverse A261294; %C A261293 a(A065650(n)) = A065650(a(n)) = A065649(n). %H A261293 Reinhard Zumkeller, <a href="/A261293/b261293.txt">Table of n, a(n) for n = 0..10000</a> %H A261293 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A261293 (Haskell) %o A261293 a261293 = a065649 . a065649 %Y A261293 Cf. A065649, A065650, A261294 (inverse), A261279 (fixed points). %K A261293 nonn %O A261293 0,3 %A A261293 _Reinhard Zumkeller_, Aug 14 2015