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A103803 Primes p such that both 2p - 15 and 2p + 15 are primes. 5

%I

%S 11,13,19,23,29,37,41,43,47,61,71,83,89,107,113,127,139,149,191,197,

%T 223,281,293,331,379,419,421,461,463,491,499,503,523,569,593,601,653,

%U 719,733,769,797,811,821,839,881,887,1049,1063,1129,1163,1181,1213,1231

%N Primes p such that both 2p - 15 and 2p + 15 are primes.

%H Harvey P. Dale, <a href="/A103803/b103803.txt">Table of n, a(n) for n = 1..1000</a>

%F p, 2p-15 and 2p+15 all are positive and are primes (hence we omit p=2).

%t Select[Range[11,2000], PrimeQ[ # ] && PrimeQ[2# + 15] && PrimeQ[2# - 15] &]

%t Select[Prime[Range[2,250]],And@@PrimeQ[2#+{15,-15}]&] (* _Harvey P. Dale_, May 21 2013 *)

%o (MAGMA) [p: p in PrimesUpTo(3200)| IsPrime(2*p+15) and IsPrime(2*p-15) ]; // _Vincenzo Librandi_, Jan 28 2011

%Y Cf. A103802.

%K nonn

%O 1,1

%A _Zak Seidov_, Feb 16 2005

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Last modified May 7 23:48 EDT 2021. Contains 343652 sequences. (Running on oeis4.)