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A103805 Primes p such that 2*p - 27 and 2*p + 27 are positive primes. 3

%I #24 Sep 08 2022 08:45:17

%S 17,23,37,43,83,103,127,197,257,307,313,317,337,373,457,673,677,727,

%T 733,797,863,887,937,953,1013,1063,1283,1303,1597,1667,1693,1777,1783,

%U 1987,1997,2053,2063,2267,2297,2393,2473,2543,2707,2777,2833,2837

%N Primes p such that 2*p - 27 and 2*p + 27 are positive primes.

%H Harvey P. Dale, <a href="/A103805/b103805.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Range[17,2000], PrimeQ[ # ] && PrimeQ[2# + 27] && PrimeQ[2# - 27] &]

%t Select[Prime[Range[5,500]],And@@PrimeQ[2#+{27,-27}]&] (* _Harvey P. Dale_, Jul 06 2013 *)

%o (Magma) [p: p in PrimesUpTo(3000) | IsPrime(2*p-27) and IsPrime(2*p+27)]; // _Vincenzo Librandi_, Nov 16 2010

%Y Cf. A103802, A103803, A103804.

%K nonn

%O 1,1

%A _Zak Seidov_, Feb 16 2005

%E More terms from _Vincenzo Librandi_, Mar 17 2010

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Last modified March 28 17:25 EDT 2024. Contains 371254 sequences. (Running on oeis4.)