The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A175416 Those positive integers n that when written in binary, each run of 0's and 1's has a length which is coprime to the number of binary digits of n. 2
 1, 2, 4, 5, 6, 8, 10, 14, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 42, 62, 64, 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, 96, 97, 98, 99, 100 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..5000 EXAMPLE 70 in binary is 1000110. There is a run of one 1, followed by a run of three 0's, followed by a run of two 1's, followed finally by a run of one 0. And there are seven binary digits all together. Since 1, 3, 2, and 1 each are coprime to 7, then 70 is in the sequence. MATHEMATICA cpQ[n_]:=Module[{d=Length/@Split[IntegerDigits[n, 2]]}, And@@CoprimeQ[ d, Total[ d]]]; Select[Range[100], cpQ] (* Harvey P. Dale, Mar 25 2013 *) CROSSREFS Cf. A175415 Sequence in context: A020640 A068383 A276603 * A190854 A069872 A216163 Adjacent sequences: A175413 A175414 A175415 * A175417 A175418 A175419 KEYWORD base,nonn AUTHOR Leroy Quet, May 07 2010 EXTENSIONS More terms from Sean A. Irvine, Mar 02 2011 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified November 28 09:43 EST 2022. Contains 358407 sequences. (Running on oeis4.)