A139706 Take n in binary. Rotate the binary digits to the right until a 1 once again appears as the leftmost digit. Convert back into decimal for a(n).

1, 2, 3, 4, 6, 5, 7, 8, 12, 10, 13, 9, 14, 11, 15, 16, 24, 20, 25, 18, 26, 21, 27, 17, 28, 22, 29, 19, 30, 23, 31, 32, 48, 40, 49, 36, 50, 41, 51, 34, 52, 42, 53, 37, 54, 43, 55, 33, 56, 44, 57, 38, 58, 45, 59, 35, 60, 46, 61, 39, 62, 47, 63, 64, 96, 80, 97, 72, 98, 81, 99, 68

Offset

1,2

Comments

This sequence written in binary is A139707.

This is a permutation of the positive integers. A139708 is the inverse permutation.

Moreover, the first 2^n terms are a permutation of the first 2^n positive integers. Fixed points of the permutation are A272919. - Ivan Neretin, May 10 2016

Links

Ivan Neretin, Table of n, a(n) for n = 1..8192

Index entries for sequences that are permutations of the natural numbers

Maple

A139706 := proc(n) local a; a := ListTools[Rotate](convert(n, base, 2), 1) ; while op(-1, a) = 0 do a := ListTools[Rotate](a, 1) ; od: add(op(i, a)*2^(i-1), i=1..nops(a)) : end: seq(A139706(n), n=1..100) ; # R. J. Mathar, May 04 2008

Mathematica

Table[FromDigits[RotateRight[IntegerDigits[n, 2], IntegerExponent[n, 2] + 1], 2], {n, 72}] (* Ivan Neretin, May 10 2016 *)

Crossrefs

Cf. A139707 (in binary), A139708 (inverse), A272919 (fixed points).

Sequence in context: A352725 A372128 A367307 * A333777 A306869 A139708

Adjacent sequences: A139703 A139704 A139705 * A139707 A139708 A139709

Keyword

nonn,base,easy

Author

Leroy Quet, Apr 30 2008

Extensions

More terms from R. J. Mathar, May 04 2008

Status

approved