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A095313
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Primes in whose binary expansion the number of 1-bits is <= 6 + number of 0-bits.
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4
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2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269
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OFFSET
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1,1
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COMMENTS
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Differs from primes (A000040) first time at n=31, where a(31)=131, while A000040(31)=127, as 127 whose binary expansion is 1111111, with 7 1-bits and no 0-bits is the first prime excluded from this sequence.
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LINKS
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MATHEMATICA
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Select[Prime[Range[100]], DigitCount[#, 2, 1]<= DigitCount[#, 2, 0]+6&] (* Harvey P. Dale, Aug 18 2016 *)
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PROG
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(PARI)forprime(p=2, 269, v=binary(p); s=0; for(k=1, #v, s+=if(v[k]==1, +1, -1)); if(s<=6, print1(p, ", "))) \\ Washington Bomfim, Jan 13 2011
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CROSSREFS
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Complement of A095312 in A000040. Subset: A095285, from which it differs first time at n=42, where a(42)=191 (10111111 in binary), while A095285(42)=193 (11000001 in binary). Cf. also A095333.
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KEYWORD
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nonn,base,easy
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AUTHOR
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STATUS
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approved
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