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Primes p such that 4p + 3 is prime.
14

%I #24 Sep 08 2022 08:44:47

%S 2,5,7,11,17,19,31,37,41,47,59,67,89,107,109,149,151,157,179,181,227,

%T 229,241,257,271,307,331,349,359,367,389,401,439,457,461,467,487,499,

%U 509,521,571,577,587,599,647,661,677,691,719,769,797,829,839,877,881,907,929,941

%N Primes p such that 4p + 3 is prime.

%H Vincenzo Librandi, <a href="/A023213/b023213.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Prime@Range@500, PrimeQ[4 # + 3] &] (* _Vincenzo Librandi_, May 19 2014 *)

%o (Magma) [ n: n in PrimesUpTo(1000) | IsPrime(4*n+3) ]; // _Vincenzo Librandi_, Nov 20 2010

%o (PARI) select(p->isprime(4*p+3),primes(100)) \\ _Charles R Greathouse IV_, Mar 21 2013

%Y Cf. A007700.

%K nonn,easy

%O 1,1

%A _David W. Wilson_