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A137703 Prime numbers p such that p +- ((p-1)/3) are primes. 1
991, 2143, 3331, 4591, 4663, 5563, 5653, 8623, 9181, 9343, 9631, 12781, 13033, 13411, 14851, 15643, 16183, 16363, 20161, 20521, 20593, 23311, 24373, 25471, 26641, 27073, 28711, 30133, 30763, 32401, 32491, 34381, 35803, 37783, 38431, 38611, 39043, 39241 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

EXAMPLE

991 is in the sequence because 991+(990/3) = 1321 and 991-(990/3) = 661, which are primes;

2143 is in the sequence because 2143+(2142/3) = 2857 and 2143-(2142/3) = 1429, which are primes.

MATHEMATICA

Select[Prime[Range[50000]], PrimeQ[# + (# - 1) / 3]&&PrimeQ[# - (# - 1) / 3]&] (* Vincenzo Librandi, Jun 15 2013 *)

PROG

(MAGMA) [p: p in PrimesInInterval(5, 40000)| IsPrime((4*p-1) div 3 ) and IsPrime((2*p+1) div 3)]; // Vincenzo Librandi, Jun 15 2013

CROSSREFS

Sequence in context: A218401 A053393 A031790 * A255098 A155509 A093177

Adjacent sequences:  A137700 A137701 A137702 * A137704 A137705 A137706

KEYWORD

nonn,easy

AUTHOR

Vladimir Joseph Stephan Orlovsky, Apr 27 2008

EXTENSIONS

More terms from Vincenzo Librandi, Jun 15 2013

STATUS

approved

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Last modified May 25 20:58 EDT 2020. Contains 334597 sequences. (Running on oeis4.)