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Primes p such that 5*p-4 is also prime.
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%I #13 Mar 15 2020 05:08:08

%S 3,7,13,31,37,43,67,109,127,139,151,163,199,211,241,277,307,349,367,

%T 373,433,457,463,547,571,601,613,661,673,709,727,739,787,811,823,853,

%U 919,967,991,1021,1087,1117,1129,1171,1231,1291,1297,1399,1471,1483,1549

%N Primes p such that 5*p-4 is also prime.

%C Previous name: Daughter primes of order 2.

%C For daughter primes of order 1 see A088878. For smallest daughter primes of order n see A136019 (also definition).

%H Amiram Eldar, <a href="/A136051/b136051.txt">Table of n, a(n) for n = 1..10000</a>

%t n = 2; a = {}; Do[If[PrimeQ[(Prime[k] + 2n)/(2n + 1)], AppendTo[a, (Prime[k] + 2n)/(2n + 1)]], {k, 1, 1500}]; a

%t (* Second program: *)

%t Select[Prime@ Range@ 250, PrimeQ[5 # - 4] &] (* _Michael De Vlieger_, Aug 04 2017 *)

%o (PARI) lista(nn) = forprime(p=2, nn, if (isprime(5*p-4), print1(p, ", ")))

%Y Cf. A088878, A091180, A136019, A136020, A136052, A136053, A136054, A136055, A136056, A136057, A136058, A136059, A136060.

%K nonn

%O 1,1

%A _Artur Jasinski_, Dec 12 2007

%E New name from _Michel Marcus_, Aug 04 2017