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A328607
Numbers whose reversed binary expansion, without the most significant digit, is a necklace.
6
0, 1, 2, 3, 4, 6, 7, 8, 12, 14, 15, 16, 24, 26, 28, 30, 31, 32, 48, 52, 56, 58, 60, 62, 63, 64, 96, 100, 104, 106, 108, 112, 116, 118, 120, 122, 124, 126, 127, 128, 192, 200, 208, 212, 216, 220, 224, 228, 232, 234, 236, 240, 244, 246, 248, 250, 252, 254, 255
OFFSET
0,3
COMMENTS
Offset is 0 to be consistent with A257250.
A necklace is a finite sequence that is lexicographically minimal among all of its cyclic rotations.
EXAMPLE
The sequence of terms together with their binary expansions and binary indices begins:
0: 0 ~ {}
1: 1 ~ {1}
2: 10 ~ {2}
3: 11 ~ {1,2}
4: 100 ~ {3}
6: 110 ~ {2,3}
7: 111 ~ {1,2,3}
8: 1000 ~ {4}
12: 1100 ~ {3,4}
14: 1110 ~ {2,3,4}
15: 1111 ~ {1,2,3,4}
16: 10000 ~ {5}
24: 11000 ~ {4,5}
26: 11010 ~ {2,4,5}
28: 11100 ~ {3,4,5}
30: 11110 ~ {2,3,4,5}
31: 11111 ~ {1,2,3,4,5}
32: 100000 ~ {6}
48: 110000 ~ {5,6}
52: 110100 ~ {3,5,6}
MATHEMATICA
neckQ[q_]:=Array[OrderedQ[{q, RotateRight[q, #]}]&, Length[q]-1, 1, And];
Select[Range[0, 100], #<=1||neckQ[Reverse[Rest[IntegerDigits[#, 2]]]]&]
CROSSREFS
The dual non-reversed version is A257250.
The dual non-reversed version involving all digits is A065609.
The version involving all digits is A328595.
The non-reversed version is A328668.
Binary necklaces are A000031.
Sequence in context: A277779 A166935 A114391 * A257250 A258209 A300630
KEYWORD
nonn
AUTHOR
Gus Wiseman, Oct 30 2019
STATUS
approved