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A164707 A positive integer n is included if all runs of 1's in binary n are of the same length. 5
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 17, 18, 20, 21, 24, 27, 28, 30, 31, 32, 33, 34, 36, 37, 40, 41, 42, 48, 51, 54, 56, 60, 62, 63, 64, 65, 66, 68, 69, 72, 73, 74, 80, 81, 82, 84, 85, 96, 99, 102, 108, 112, 119, 120, 124, 126, 127, 128, 129, 130, 132, 133, 136 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

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.

This sequence contains in part positive integers that each contain one run of 1's. For those members of this sequence each with at least two runs of 1's, see A164709.

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

MAPLE

isA164707 := proc(n) local bdg, arl, lset ; bdg := convert(n, base, 2) ; lset := {} ; arl := -1 ; for p from 1 to nops(bdg) do if op(p, bdg) = 1 then if p = 1 then arl := 1 ; else arl := arl+1 ; end if; else if arl > 0 then lset := lset union {arl} ; end if; arl := 0 ; end if; end do ; if arl > 0 then lset := lset union {arl} ; end if; return (nops(lset) <= 1 ); end proc: for n from 1 to 300 do if isA164707(n) then printf("%d, ", n) ; end if; end do; # R. J. Mathar, Feb 27 2010

MATHEMATICA

Select[Range@ 140, SameQ @@ Map[Length, Select[Split@ IntegerDigits[#, 2], First@ # == 1 &]] &] (* Michael De Vlieger, Aug 20 2017 *)

PROG

(Perl)

foreach(1..140){

    %runs=();

    $runs{$_}++ foreach split /0+/, sprintf("%b", $_);

    print "$_, " if 1==keys(%runs);

}

# Ivan Neretin, Nov 09 2015

CROSSREFS

Cf. A164708, A164709, A164710.

Sequence in context: A045779 A235028 A062014 * A057890 A161604 A125121

Adjacent sequences:  A164704 A164705 A164706 * A164708 A164709 A164710

KEYWORD

base,nonn

AUTHOR

Leroy Quet, Aug 23 2009

EXTENSIONS

Extended beyond 42 by R. J. Mathar, Feb 27 2010

STATUS

approved

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Last modified March 18 22:11 EDT 2019. Contains 321305 sequences. (Running on oeis4.)