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 A238758 #13 Mar 10 2014 09:27:01
%S A238758 1,2,5,4,3,10,9,8,7,6,12,11,17,18,20,16,13,14,24,15,26,25,33,19,22,21,
%T A238758 34,36,35,37,40,32,23,27,29,28,30,41,48,31,38,49,52,50,65,66,68,39,42,
%U A238758 44,69,43,67,74,73,72,71,70,76,75,80,81
%N A238758 Lexicographically earliest sequence of distinct positive integers such that a(n) AND n is a power of 2 for any n>0 (AND stands for the bitwise AND operator).
%C A238758 This is a permutation of the positive integers.
%C A238758 Apparently, a self-inverse permutation.
%C A238758 The powers of 2 (A000079) are the fixed points.
%H A238758 Paul Tek, <a href="/A238758/b238758.txt">Table of n, a(n) for n = 1..10000</a>
%H A238758 Paul Tek, <a href="/A238758/a238758.txt">Perl program for this sequence</a>
%H A238758 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%t A238758 s = {}; Do[j=1; While[ MemberQ[s,j] || (b = BitAnd[j, n]) == 0 || BitAnd[b, b-1] > 0, j++]; AppendTo[s, j], {n, 62}]; s (* _Giovanni Resta_, Mar 05 2014 *)
%o A238758 (Perl) See Link section.
%Y A238758 Cf. A238757.
%K A238758 nonn
%O A238758 1,2
%A A238758 _Paul Tek_, Mar 05 2014