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A095323
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Primes in whose binary expansion the number of 1-bits is <= 4 + number of 0-bits.
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4
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2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 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, 193, 197, 199, 211, 227, 229, 233, 241, 257, 263, 269, 271, 277, 281, 283, 293
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Differs from primes (A000040) first time at n=11, where a(11)=37, while A000040(11)=31, as 31 whose binary expansion is 11111, with 5 1-bits and no 0-bits is the first prime excluded from this sequence. Note that 15 (1111 in binary) is not prime.
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LINKS
| A. Karttunen and J. Moyer: C-program for computing the initial terms of this sequence
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PROG
| (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 <= (4+b0), return(1); , return(0); ); };
forprime(x = 2, 293, if(B(x), print1(x, ", "); ); );
[W. Bomfim webonfim(AT)bol.com Jan 12, 2011]
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CROSSREFS
| Complement of A095322 in A000040. Subset of A095285. subset: A095319. A095325.
Sequence in context: A051750 A100724 A100110 * A100370 A095319 A129621
Adjacent sequences: A095320 A095321 A095322 * A095324 A095325 A095326
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KEYWORD
| nonn,base,easy
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AUTHOR
| Antti Karttunen (his-firstname.his-surname(AT)iki.fi), Jun 04 2004
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