cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A095314 Primes in whose binary expansion the number of 1 bits is > 2 + number of 0 bits.

Original entry on oeis.org

7, 23, 29, 31, 47, 59, 61, 79, 103, 107, 109, 127, 191, 223, 239, 251, 311, 317, 347, 349, 359, 367, 373, 379, 383, 431, 439, 443, 461, 463, 467, 479, 487, 491, 499, 503, 509, 607, 631, 701, 719, 727, 733, 743, 751, 757, 761, 823, 827, 829, 859
Offset: 1

Views

Author

Antti Karttunen, Jun 04 2004

Keywords

Crossrefs

Complement of A095315 in A000040. Subset of A095286. Subset: A095318. Cf. also A095334.

Programs

  • Maple
    f:= proc(n) local L,d,s;
        if not isprime(n) then return false fi;
        L:= convert(n,base,2);
        convert(L,`+`) > nops(L)/2+1
    end proc:
    select(f, [seq(i,i=3..1000,2)]); # Robert Israel, Oct 26 2023
  • Mathematica
    n1Q[p_]:=Module[{be=IntegerDigits[p,2]},Total[be]>2+Count[be,0]]; Select[ Prime[ Range[150]],n1Q] (* Harvey P. Dale, Oct 26 2022 *)
  • PARI
    B(x) = { nB = floor(log(x)/log(2)); b1 = 0; b0 = 0;
    for(i = 0, nB, if(bittest(x,i), b1++;, b0++;); );
    if(b1 > (2+b0), return(1);, return(0););};
    forprime(x = 2, 859, if(B(x), print1(x, ", "); ); );
    \\ Washington Bomfim, Jan 12 2011