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).

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, 34, 36, 35, 37, 40, 32, 23, 27, 29, 28, 30, 41, 48, 31, 38, 49, 52, 50, 65, 66, 68, 39, 42, 44, 69, 43, 67, 74, 73, 72, 71, 70, 76, 75, 80, 81

Offset: 1

Author

Paul Tek, Mar 05 2014

Keywords

• nonn

Comments

This is a permutation of the positive integers.

Apparently, a self-inverse permutation.

The powers of 2 (A000079) are the fixed points.

Links

• Paul Tek, Table of n, a(n) for n = 1..10000
• Paul Tek, Perl program for this sequence
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A238757.

Programs

Mathematica

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 *)

Perl

See Link section.