login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A065879 Lowest positive number that is n times the number of 1's in its binary expansion, or 0 if no such number exists. 5

%I

%S 1,2,6,4,10,12,21,8,18,20,55,24,0,42,60,16,34,36,0,40,126,110,69,48,0,

%T 0,81,84,116,120,155,32,66,68,0,72,185,0,156,80,205,252,172,220,180,

%U 138,0,96,0,0,204,0,212,162,0,168,228,232,295,240,366,310,378,64,130

%N Lowest positive number that is n times the number of 1's in its binary expansion, or 0 if no such number exists.

%C a(n) is bounded above by n*A272756(n), so a program only has to check values up to that point to see if a(n) is zero. - _Peter Kagey_, May 05 2016

%H Peter Kagey, <a href="/A065879/b065879.txt">Table of n, a(n) for n = 1..10000</a>

%e a(23) is 69 since 69 is written in binary as 1000101, 69/(1+0+0+0+1+0+1)=23 and there is no lower possibility (neither 23 nor 46 are divisible by their number of binary 1's).

%t Table[SelectFirst[Range[2^12], # == n First@ DigitCount[#, 2] &] /. k_ /; MissingQ@ k -> 0, {n, 80}] (* _Michael De Vlieger_, May 05 2016, Version 10.2 *)

%Y A003634 is the base 10 equivalent.

%Y Cf. A000120, A049445, A058898, A065413, A065878, A065880, A272756.

%K base,nonn

%O 1,2

%A _Henry Bottomley_, Nov 26 2001

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 10 04:15 EST 2019. Contains 329885 sequences. (Running on oeis4.)