A257739 Numbers n for which A256999(n) > n; numbers that can be made larger by rotating (by one or more steps) the non-msb bits of their binary representation (with A080541 or A080542).

5, 9, 10, 11, 13, 17, 18, 19, 20, 21, 22, 23, 25, 27, 29, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 53, 54, 55, 57, 59, 61, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 97, 98, 99, 101, 102, 103, 105, 107, 108, 109, 110, 111

Offset

1,1

Comments

Note that A256999(a(n)) is always in A257250.

If we define a co-necklace to be a finite sequence that is lexicographically maximal (not minimal) among all of its cyclic rotations, these are numbers whose binary expansion, without the most significant digit, is not a co-necklace. Numbers whose binary expansion, without the most significant digit, is not a necklace are A329367. - Gus Wiseman, Nov 14 2019

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Example

For n = 5 with binary representation "101" if we rotate other bits than the most significant bit (that is, only the two rightmost digits "01") one step to either direction we get "110" = 6 > 5, so 5 can be made larger by such rotations and thus 5 is included in this sequence.
For n = 6 with binary representation "110" no such rotation will yield a larger number and thus 6 is NOT included in this sequence.
For n = 10 with binary representation "1010" if we rotate other bits than the most significant bit (that is, only the three rightmost digits "010") either one step to the left or two steps to the right we get "1100" = 12 > 10, thus 10 is included in this sequence.

Mathematica

reckQ[q_]:=Array[OrderedQ[{RotateRight[q, #], q}]&, Length[q]-1, 1, And];
Select[Range[2, 100], !reckQ[Rest[IntegerDigits[#, 2]]]&] (* Gus Wiseman, Nov 14 2019 *)

Prog

(Scheme, with Antti Karttunen's IntSeq-library)
(define A257739 (MATCHING-POS 1 1 (lambda (n) (< n (A256999 n)))))

Crossrefs

Complement: A257250.

Cf. A080541, A080542, A256999.

Numbers whose binary expansion is a necklace are A275692.

Numbers whose binary expansion is a co-necklace are A065609.

Numbers whose reversed binary expansion is a necklace are A328595.

Numbers whose non-msb expansion is a co-necklace are A257250.

Numbers whose non-msb expansion is a necklace are A328668.

Numbers whose reversed non-msb expansion is a necklace are A328607.

Numbers whose non-msb expansion is not a necklace are A329367.

Binary necklaces are A000031.

Necklace compositions are A008965.

Cf. A000120, A001037, A003714, A014081, A121016, A164707, A328594, A328596.

Sequence in context: A277706 A300669 A166934 * A094695 A268412 A043682

Adjacent sequences: A257736 A257737 A257738 * A257740 A257741 A257742

Keyword

nonn,base

Author

Antti Karttunen, May 18 2015

Status

approved