A043725 - OEIS

A043725

Numbers whose number of runs in the base-2 representation is congruent to 1 mod 4.

1, 3, 7, 15, 21, 31, 37, 41, 43, 45, 53, 63, 69, 73, 75, 77, 81, 83, 87, 89, 91, 93, 101, 105, 107, 109, 117, 127, 133, 137, 139, 141, 145, 147, 151, 153, 155, 157, 161, 163, 167, 175, 177, 179, 183, 185, 187, 189, 197, 201, 203, 205

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OFFSET

1,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Paul Barry, Conjectures and results on some generalized Rueppel sequences, arXiv:2107.00442 [math.CO], 2021.

MATHEMATICA

Select[Range[250], Mod[Length[Split[IntegerDigits[#, 2]]], 4]==1&] (* Harvey P. Dale, Dec 10 2018 *)

CROSSREFS

Sequence in context: A153830 A080550 A348943 * A182247 A121712 A175544

Adjacent sequences: A043722 A043723 A043724 * A043726 A043727 A043728

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved