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A066148
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Primes with an even number of 0's in binary expansion.
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5
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3, 7, 19, 31, 43, 53, 67, 73, 79, 97, 103, 107, 109, 127, 139, 149, 163, 197, 271, 283, 307, 313, 331, 367, 379, 397, 409, 419, 421, 431, 433, 439, 443, 457, 463, 487, 491, 499, 523, 547, 571, 593, 599, 619, 643, 673, 683, 691, 739, 751, 773, 797, 811, 821
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OFFSET
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1,1
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LINKS
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T. D. Noe, Table of n, a(n) for n=1..1000
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PROG
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(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)
(PARI) baseE(x, b)= { local(d, e=0, f=1); while (x>0, d=x-b*(x\b); x\=b; e+=d*f; f*=10); return(e) } Count(x, d)= { local(c=0, f); while (x>9, f=x%10; if (f==d, c++); x\=10); if (x==d, c++); return(c) } { n=0; for (m=1, 10^9, p=prime(m); b=baseE(p, 2); if (Count(b, 0)%2 == 0, write("b066148.txt", n++, " ", p); if (n==1000, return)) ) } [From Harry J. Smith, Feb 02 2010]
(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, ", "))) [W. Bomfim webonfim(AT)bol.com Jan 14, 2011]
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CROSSREFS
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Cf. A066149, A027699, A027697.
Cf. A059010
Sequence in context: A091738 A136054 A006032 * A093932 A141173 A145472
Adjacent sequences: A066145 A066146 A066147 * A066149 A066150 A066151
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KEYWORD
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nonn,easy,base,changed
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AUTHOR
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R. K. Guy, Dec 13, 2001
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EXTENSIONS
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More terms from Vladeta Jovovic and Klaus Brockhaus, Dec 13 2001
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STATUS
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approved
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