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.

A095071 Zero-bit dominant primes, i.e., primes whose binary expansion contains more 0's than 1's.

Original entry on oeis.org

17, 67, 73, 97, 131, 137, 193, 257, 263, 269, 277, 281, 293, 337, 353, 389, 401, 449, 521, 523, 547, 577, 593, 641, 643, 673, 769, 773, 1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069, 1091, 1093, 1097, 1109, 1123, 1129, 1153, 1163, 1171
Offset: 1

Views

Author

Antti Karttunen, Jun 01 2004

Keywords

Examples

			73 is in the sequence because 73 is a prime and 73_10 = 1001001_2. '1001001' has four 0's and one 1. - _Indranil Ghosh_, Jan 31 2017
		

Crossrefs

Complement of A095074 in A000040. Subset: A095072. Cf. A095019.

Programs

  • Mathematica
    Reap[Do[p=Prime[k];id=IntegerDigits[p,2];n=Length@id;If[Count[id,0]>n/2,Sow[p]],{k,200}]][[2,1]]
    (* Zak Seidov *)
    Select[Prime[Range[200]],DigitCount[#,2,0]>DigitCount[#,2,1]&] (* Harvey P. Dale, Nov 28 2024 *)
  • PARI
    B(x) = { nB = floor(log(x)/log(2)); b1 = 0; b0 = 0;
    for(i = 0, nB, if(bittest(x,i), b1++;, b0++;); );
    if(b0 > b1, return(1);, return(0););};
    forprime(x = 2, 1171, if(B(x), print1(x, ", "); ); ); \\ Washington Bomfim, Jan 11 2011
    
  • PARI
    {forprime(p=2,1171,nB=floor(log(p)/log(2));
    sum(i=0,nB,bittest(p,i))<=nB/2&print1(p,","))} \\ Zak Seidov, Jan 11 2011
    
  • Python
    #Program to generate the b-file
    from sympy import isprime
    i=1
    j=1
    while j<=200:
        if isprime(i) and bin(i)[2:].count("0")>bin(i)[2:].count("1"):
            print(str(j)+" "+str(i))
            j+=1
        i+=1 # Indranil Ghosh, Jan 31 2017