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A063911 Numbers n such that n and 2n-9 are primes. 2
7, 11, 13, 19, 23, 31, 41, 53, 59, 61, 73, 79, 83, 101, 103, 139, 151, 163, 173, 179, 181, 191, 199, 229, 233, 283, 293, 311, 313, 331, 359, 383, 389, 409, 419, 431, 433, 443, 503, 509, 521, 563, 569, 601, 613, 619, 643, 653, 691, 709, 719 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..1000

MATHEMATICA

Select[Prime[Range[3, 2000]], PrimeQ[2 # - 9]&] (* Vincenzo Librandi, Feb 02 2014

PROG

(PARI) { n=0; p=1; for (m=1, 10^9, p=nextprime(p+1); if (isprime(2*p - 9), write("b063911.txt", n++, " ", p); if (n==1000, break)) ) } \\ Harry J. Smith, Sep 02 2009

(MAGMA) [n: n in [4..2000] | IsPrime(n) and IsPrime(2*n-9)]; // Vincenzo Librandi, Feb 02 2014

CROSSREFS

Sequence in context: A091932 A165349 A160024 * A087489 A155488 A100350

Adjacent sequences:  A063908 A063909 A063910 * A063912 A063913 A063914

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Aug 31 2001

STATUS

approved

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Last modified August 23 14:17 EDT 2019. Contains 326247 sequences. (Running on oeis4.)