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A066179
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n, (n-1)/2, (n-3)/4 all prime.
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8
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11, 23, 47, 167, 359, 719, 1439, 2039, 2879, 4079, 4127, 4919, 5639, 5807, 5927, 6047, 7247, 7559, 7607, 7727, 9839, 10799, 11279, 13799, 13967, 14159, 15287, 15647, 20327, 21599, 21767, 23399, 24407, 24527, 25799, 28319, 28607, 29399
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Call p m-prime iff (p-(2^i-1))/2^i is prime for i=0 .. m; sequence gives 2-primes. 0-primes are primes (A000040) and 1-primes are safe primes (A005385). a(n)-1 and a(n) are consecutive terms of the sequence A065966. It is not known if there are infinitely many m-primes for m > 0.
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LINKS
| Harry J. Smith, Table of n, a(n) for n=1,...,1000
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MATHEMATICA
| lst={}; Do[p=Prime[n]; If[PrimeQ[a=(p-1)/2]&&PrimeQ[(a-1)/2], AppendTo[lst, p]], {n, 8!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Feb 27 2009]
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PROG
| (PARI) { n=0; default(primelimit, 4294965247); for (m=1, 10^9, p=prime(m); if (frac((p-3)/4), next); if (isprime((p-3)/4) && isprime((p-1)/2), write("b066179.txt", n++, " ", p); if (n==1000, return)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Feb 05 2010]
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CROSSREFS
| Sequence in context: A100558 A126199 A096342 * A141093 A041236 A097485
Adjacent sequences: A066176 A066177 A066178 * A066180 A066181 A066182
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KEYWORD
| nonn
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AUTHOR
| Vladeta Jovovic (vladeta(AT)eunet.rs), Dec 14 2001
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EXTENSIONS
| OFFSET changed from 0,1 to 1,1 by Harry J. Smith (hjsmithh(AT)sbcglobal.net), Feb 05 2010
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