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%I #20 Sep 08 2022 08:45:33
%S 991,2143,3331,4591,4663,5563,5653,8623,9181,9343,9631,12781,13033,
%T 13411,14851,15643,16183,16363,20161,20521,20593,23311,24373,25471,
%U 26641,27073,28711,30133,30763,32401,32491,34381,35803,37783,38431,38611,39043,39241
%N Prime numbers p such that p +- ((p-1)/3) are primes.
%H Vincenzo Librandi, <a href="/A137703/b137703.txt">Table of n, a(n) for n = 1..1000</a>
%e 991 is in the sequence because 991+(990/3) = 1321 and 991-(990/3) = 661, which are primes;
%e 2143 is in the sequence because 2143+(2142/3) = 2857 and 2143-(2142/3) = 1429, which are primes.
%t Select[Prime[Range[50000]], PrimeQ[# + (# - 1) / 3]&&PrimeQ[# - (# - 1) / 3]&] (* _Vincenzo Librandi_, Jun 15 2013 *)
%o (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
%K nonn,easy
%O 1,1
%A _Vladimir Joseph Stephan Orlovsky_, Apr 27 2008
%E More terms from _Vincenzo Librandi_, Jun 15 2013
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