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A238757 Lexicographically earliest sequence of distinct positive integers such that for any n>0 we have (a(n) AND n) = 0 (where AND stands for the bitwise AND operator).

%I A238757 #22 Jun 22 2022 07:34:45
%S A238757 2,1,4,3,8,9,16,5,6,17,20,18,32,33,48,7,10,12,36,11,34,40,64,35,38,37,
%T A238757 68,65,66,96,128,13,14,21,24,19,26,25,72,22,70,69,80,67,82,81,144,15,
%U A238757 74,73,76,75,130,129,136,71,132,133,192,131,194,193,256,23
%N A238757 Lexicographically earliest sequence of distinct positive integers such that for any n>0 we have (a(n) AND n) = 0 (where AND stands for the bitwise AND operator).
%C A238757 This is a permutation of the positive integers.
%C A238757 Apparently, a self-inverse permutation.
%C A238757 There are no fixed points.
%H A238757 Paul Tek, <a href="/A238757/b238757.txt">Table of n, a(n) for n = 1..10000</a>
%H A238757 Paul Tek, <a href="/A238757/a238757.txt">Perl program for this sequence</a>
%H A238757 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%o A238757 (Perl) See Link section.
%o A238757 (Python)
%o A238757 from itertools import count, islice
%o A238757 def agen(): # generator of terms
%o A238757     aset, mink = set(), 1
%o A238757     for n in count(1):
%o A238757         an = mink
%o A238757         while an in aset or n&an: an += 1
%o A238757         aset.add(an); yield an
%o A238757         while mink in aset: mink += 1
%o A238757 print(list(islice(agen(), 64))) # _Michael S. Branicky_, Jun 22 2022
%Y A238757 Cf. A238758.
%K A238757 nonn
%O A238757 1,1
%A A238757 _Paul Tek_, Mar 05 2014