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 A266642 #11 Jan 09 2016 16:07:50 %S A266642 0,1,2,3,4,5,6,13,8,9,10,7,12,11,14,15,32,29,18,23,20,33,50,17,24,49, %T A266642 22,27,28,25,30,41,16,21,34,19,36,31,26,57,40,37,42,125,68,45,106,55, %U A266642 96,71,38,81,88,89,54,101,56,117,118,61,60,83,82,99,116,65,78,119,52,51,70,113,72,77,62,75,92,43,114,107,80,69 %N A266642 Permutation of nonnegative integers: a(n) = A264966(2*n) / 2. %H A266642 Antti Karttunen, <a href="/A266642/b266642.txt">Table of n, a(n) for n = 0..9842</a> %H A266642 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A266642 a(n) = A264966(2*n) / 2. %F A266642 As a composition of related permutations: %F A266642 a(n) = A057889(A263272(n)). %o A266642 (Scheme) (define (A266642 n) (/ (A264966 (* 2 n)) 2)) %Y A266642 Inverse: A266641. %Y A266642 Cf. A057889, A263272, A264966, A265329, A265369, A266635, A266636, A266643, A266644. %K A266642 nonn,base %O A266642 0,3 %A A266642 _Antti Karttunen_, Jan 04 2016