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A095079 Primes with two 0-bits in their binary expansion.

%I A095079 #15 Dec 27 2023 11:58:12
%S A095079 19,43,53,79,103,107,109,367,379,431,439,443,463,487,491,499,751,863,
%T A095079 887,983,1013,1279,1471,1531,1663,1759,1783,1787,1789,1951,1979,1999,
%U A095079 2011,2027,2029,3067,3581,3823,4027,5119,6079,6911,7039,7103
%N A095079 Primes with two 0-bits in their binary expansion.
%H A095079 Alois P. Heinz, <a href="/A095079/b095079.txt">Table of n, a(n) for n = 1..10000</a>
%H A095079 A. Karttunen and J. Moyer, <a href="/A095062/a095062.c.txt">C-program for computing the initial terms of this sequence</a>
%t A095079 Select[Prime[Range[1000]], DigitCount[#, 2, 0] == 2 &]
%o A095079 (PARI)
%o A095079 { forprime(p=2,8000,
%o A095079   v=binary(p); s=0;
%o A095079   for(k=1,#v, s+=if(v[k]==0,+1,0));
%o A095079   if(s==2,print1(p,", "))
%o A095079 ) }
%o A095079 (Python)
%o A095079 from sympy import isprime
%o A095079 from itertools import combinations, count, islice
%o A095079 def agen(): # generator of terms
%o A095079     for d in count(2):
%o A095079         b = (1<<(d+2))-1
%o A095079         for i, j in combinations(range(d), 2):
%o A095079             if isprime(t:=b-(1<<(d-i))-(1<<(d-j))):
%o A095079                 yield t
%o A095079 print(list(islice(agen(), 43))) # _Michael S. Branicky_, Dec 27 2023
%Y A095079 Cf. A095059.
%K A095079 nonn,base,easy
%O A095079 1,1
%A A095079 _Antti Karttunen_, Jun 01 2004