A171832 - OEIS

A171832

Primes p such that p and 5*p^2+5*p-1 are both prime

%I #15 Sep 08 2022 08:45:50

%S 2,3,5,11,29,41,47,137,197,227,251,269,293,353,359,383,401,467,641,

%T 659,701,797,839,857,929,1103,1163,1193,1229,1259,1289,1319,1373,1439,

%U 1451,1487,1523,1553,1559,1721,1787,1847,1871,1877,1889,1913,1949,2081

%N Primes p such that p and 5*p^2+5*p-1 are both prime

%H Harvey P. Dale, <a href="/A171832/b171832.txt">Table of n, a(n) for n = 1..3000</a>

%t Select[Prime[Range[400]],PrimeQ[5#^2+5#-1]&] (* _Harvey P. Dale_, Apr 03 2010 *)

%o (Magma) [p: p in PrimesUpTo(2500) | IsPrime(5*p^2+5*p-1)]; // _Vincenzo Librandi_, Aug 20 2014

%o (PARI) lista(nn) = {forprime(p=2, nn, if (isprime(5*p^2+5*p-1), print1(p, ", ")););} \\ _Michel Marcus_, Aug 20 2014

%K nonn

%O 1,1

%A _Vincenzo Librandi_, Dec 19 2009

%E Corrected sequence because 1553 had been omitted _Harvey P. Dale_, Apr 03 2010