A281553 Write n in binary reflected Gray code, rotate one binary place to the right and convert the code back to decimal.

0, 1, 3, 1, 3, 7, 6, 2, 6, 14, 15, 7, 5, 13, 12, 4, 12, 28, 29, 13, 15, 31, 30, 14, 10, 26, 27, 11, 9, 25, 24, 8, 24, 56, 57, 25, 27, 59, 58, 26, 30, 62, 63, 31, 29, 61, 60, 28, 20, 52, 53, 21, 23, 55, 54, 22, 18, 50, 51, 19, 17, 49, 48, 16, 48, 112, 113, 49, 51, 115, 114, 50, 54, 118

Offset

0,3

Comments

a(n) = A003188(n), iff the Elias delta code for n contains all 1's without any zeros (see the example section).

Links

Indranil Ghosh, Table of n, a(n) for n = 0..10000

Example

For n = 5, the binary reflected Gray code for n is '111'. Rotating one binary place to the right , '111' gives back '111' again. 111_2 = 7_10. So, a(5) = 7. (For n = 5, A003188(n) = 7).
For n = 15, the binary reflected Gray code for n is '1000'. Rotating one binary place to the right, '1000' gives '0100'. 100_2 = 4_10. So, a(15) = 4.

Prog

(Python)
def rotation(n):
....x=bin(n^(n/2))[2:]
....return int(x[-1]+x[:-1], 2)

Crossrefs

Cf. A003188, A014550, A038572.

Sequence in context: A035619 A280995 A092689 * A064434 A328988 A086401

Adjacent sequences: A281550 A281551 A281552 * A281554 A281555 A281556

Keyword

nonn,base

Author

Indranil Ghosh, Jan 24 2017

Status

approved