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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).
7
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
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
KEYWORD
nonn,base,easy
AUTHOR
Leroy Quet, Apr 30 2008
EXTENSIONS
More terms from R. J. Mathar, May 04 2008
STATUS
approved