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Primes with an even number of 0's in binary expansion.
5

%I #27 Jun 16 2018 18:36:57

%S 3,7,19,31,43,53,67,73,79,97,103,107,109,127,139,149,163,197,271,283,

%T 307,313,331,367,379,397,409,419,421,431,433,439,443,457,463,487,491,

%U 499,523,547,571,593,599,619,643,673,683,691,739,751,773,797,811,821

%N Primes with an even number of 0's in binary expansion.

%H T. D. Noe, <a href="/A066148/b066148.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Prime[Range[200]],EvenQ[DigitCount[#,2,0]]&] (* _Harvey P. Dale_, Mar 04 2017 *)

%o (PARI): a066148(m) = local(p,v,z); forprime(p=2,m,v=binary(p); z=0; for(j=1,matsize(v)[2], if(v[j]==0,z++)); if(z%2==0,print1(p,","))) a066148(850)

%o (PARI) f(p)={v=binary(p);s=0;for(k=1,#v,if(v[k]==0, s++));return(1-s%2)};forprime(p=3,821,if(f(p),print1(p,", "))) \\ _Washington Bomfim_, Jan 14 2011

%o (PARI) forprime(p=2, 10^3, if( #select(x->x==0, digits(p,2))%2==0, print1(p,", "))); \\ _Joerg Arndt_, Jun 16 2018

%Y Cf. A066149, A027699, A027697.

%Y Cf. A059010

%K nonn,easy,base

%O 1,1

%A _R. K. Guy_, Dec 13 2001

%E More terms from _Vladeta Jovovic_ and _Klaus Brockhaus_, Dec 13 2001