A071849 Numbers k such that A245788(k) > prime(k).

3, 7, 11, 15, 23, 27, 29, 30, 31, 47, 55, 59, 61, 62, 63, 95, 111, 119, 123, 125, 126, 127, 159, 175, 183, 187, 189, 191, 223, 239, 247, 251, 253, 254, 255, 319, 351, 367, 375, 379, 381, 382, 383, 415, 431, 439, 447, 479, 495, 503, 507, 509, 510, 511, 639, 703

Offset: 1

Author

Benoit Cloitre, Jun 09 2002

Keywords

• base
• easy
• nonn

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000040, A000120, A245788.

Programs

Maple

p:= 1: Res:= NULL: count:= 0:
for n from 1 while count < 100 do
  p:= nextprime(p);
  if n*convert(convert(n,base,2),`+`) > p then
    count:= count+1; Res:= Res, n;
  fi
od:
Res; # Robert Israel, Oct 30 2018

Mathematica

Select[Range[700], # * DigitCount[#, 2, 1] > Prime[#] &] (* Amiram Eldar, Jun 03 2022 *)

PARI

for(n=1,1000,b=binary(n); if(sum(i=1,length(b), component(b,i))*n>prime(n),print1(n,",")))

PARI

is(n,p=prime(n))=hammingweight(n)*n>p \\ Charles R Greathouse IV, Oct 30 2018

PARI

list(lim)=my(v=List(),n); forprime(p=2,, if(n++>lim, return(Vec(v))); if(hammingweight(n)*n>p, listput(v,n))); \\ Charles R Greathouse IV, Oct 30 2018