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A063908
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Numbers n such that n and 2n-3 are primes.
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21
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3, 5, 7, 11, 13, 17, 23, 31, 37, 41, 43, 53, 67, 71, 83, 97, 101, 107, 113, 127, 137, 157, 167, 181, 191, 193, 211, 223, 233, 241, 251, 263, 283, 311, 317, 331, 347, 373, 421, 431, 433, 443, 457, 461, 487, 521, 547, 563, 577, 587, 613, 617, 631
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| If p is in this sequence then the products of positive powers of 3, p and 2p-3 are entries in A086486 - Victoria A Sapko (vsapko(AT)canes.gsw.edu), Sep 23 2003
Median prime of AP3's starting at 3, i.e. triplets of primes (3,p,q) in arithmetic progression. [From M. F. Hasler (www.univ-ag.fr/~mhasler), Sep 24 2009]
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LINKS
| Harry J. Smith, Table of n, a(n) for n=1,...,1000
C. Rivera, Puzzle 34.- Prime Triplets in arithmetic progression. [From M. F. Hasler (www.univ-ag.fr/~mhasler), Sep 24 2009]
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MATHEMATICA
| Select[Prime[Range[6! ]], PrimeQ[2*#-3]&] [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Nov 17 2009]
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PROG
| (PARI) { n=0; p=1; for (m=1, 10^9, p=nextprime(p+1); if (isprime(2*p - 3), write("b063908.txt", n++, " ", p); if (n==1000, break)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 02 2009]
(PARI) forprime( p=1, default(primelimit), isprime(2*p-3) && print1(p", ")) [From M. F. Hasler (www.univ-ag.fr/~mhasler), Sep 24 2009]
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CROSSREFS
| Cf. A005382.
Sequence in context: A147545 A083668 A176116 * A154868 A020628 A108816
Adjacent sequences: A063905 A063906 A063907 * A063909 A063910 A063911
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Aug 31 2001
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