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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
OFFSET
1,1
LINKS
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: A053393 A365598 A031790 * A255098 A155509 A093177
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
More terms from Vincenzo Librandi, Jun 15 2013
STATUS
approved