login
A164712
A positive integer n is included if all runs of 0's in binary n are of the same length, and if there are at least two runs of 0's.
3
10, 21, 22, 26, 36, 42, 43, 45, 46, 53, 54, 58, 73, 76, 85, 86, 87, 90, 91, 93, 94, 100, 106, 107, 109, 110, 117, 118, 122, 136, 147, 153, 156, 170, 171, 173, 174, 175, 181, 182, 183, 186, 187, 189, 190, 201, 204, 213, 214, 215, 218, 219, 221, 222, 228, 234, 235
OFFSET
1,1
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.
LINKS
EXAMPLE
100 is a term since its binary expansion "1100100" has two groups of zeros that are of the same length. - Michael De Vlieger, Nov 04 2017
MATHEMATICA
brQ[n_]:=Module[{rz=Select[Split[IntegerDigits[n, 2]], MemberQ[#, 0]&]}, Length[ rz]>1 && Length[Union[Length/@rz]]==1]; Select[Range[250], brQ] (* Harvey P. Dale, Mar 23 2015 *)
Select[Range[2^8], And[Length@ # > 1, Length@ Union@ # == 1] &@ Map[Length, Select[Split@ IntegerDigits[#, 2], First@ # == 0 &]] &] (* Michael De Vlieger, Nov 04 2017 *)
CROSSREFS
Cf. A164710.
Sequence in context: A251128 A244539 A335236 * A336558 A374897 A338908
KEYWORD
base,nonn
AUTHOR
Leroy Quet, Aug 23 2009
EXTENSIONS
More terms from Sean A. Irvine, Sep 28 2009
STATUS
approved