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Primes p such that 4*p+9, 8*p+21 are both prime.
1

%I #8 Sep 08 2022 08:45:41

%S 2,5,11,37,41,47,67,97,137,151,191,197,211,251,277,307,317,401,421,

%T 431,607,617,881,967,1031,1201,1307,1367,1427,1511,1531,1747,1831,

%U 1867,2221,2281,2347,2381,2531,2791,2797,2857,2897,2917,3037,3061,3271,3541,3677

%N Primes p such that 4*p+9, 8*p+21 are both prime.

%H Vincenzo Librandi, <a href="/A156014/b156014.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Prime[Range[4000]], And @@ PrimeQ[{4# + 9, 8# + 21}]&] (* _Vincenzo Librandi_, Oct 31 2012 *)

%o (Magma) [p: p in PrimesUpTo(4000)|IsPrime(4*p + 9) and IsPrime (8*p + 21)]; // _Vincenzo Librandi_, Oct 31 2012

%Y Cf. A156010.

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Feb 01 2009