A164709 A positive integer n is included if all runs of 1's in binary n are of the same length, and if there are at least two runs of 1's.

5, 9, 10, 17, 18, 20, 21, 27, 33, 34, 36, 37, 40, 41, 42, 51, 54, 65, 66, 68, 69, 72, 73, 74, 80, 81, 82, 84, 85, 99, 102, 108, 119, 129, 130, 132, 133, 136, 137, 138, 144, 145, 146, 148, 149, 160, 161, 162, 164, 165, 168, 169, 170, 195, 198, 204, 216, 219, 231, 238

Offset: 1

Author

Leroy Quet, Aug 23 2009

Keywords

• base
• nonn

Comments

Clarification: A binary number consists of "runs" completely of 1's alternating with runs completely of 0's. No two or more runs all of the same digit are adjacent.

For the terms of this sequence together with those positive integers that, when written in binary, each contain only one run of 1's, see A164707.

Links

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

Crossrefs

Cf. A164707.

Programs

Mathematica

r1slQ[n_]:=Module[{idn=Select[Split[IntegerDigits[n,2]],MemberQ[ #,1]&]}, Length[ idn]>1 && Length[Union[Length/@idn]]==1]; Select[ Range[ 250], r1slQ] (* Harvey P. Dale, Sep 29 2018 *)

Extensions

Extended by Ray Chandler, Mar 15 2010