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Primes p such that pp'-2 is prime, where p' denotes the next prime after p.
3

%I #15 Aug 05 2024 15:48:07

%S 3,157,211,257,367,557,977,997,1381,1511,1531,2467,2503,2621,2777,

%T 2861,3049,3307,3617,4099,4357,4373,4397,4463,4523,4691,4831,4919,

%U 5087,5209,5261,5351,5407,5483,5807,6173,6229,6287,6619,6871,7001,7187,7459,7577

%N Primes p such that pp'-2 is prime, where p' denotes the next prime after p.

%H Amiram Eldar, <a href="/A048797/b048797.txt">Table of n, a(n) for n = 1..10000</a>

%e 3*5 - 2 = 13, a prime, so 3 is a term of the sequence.

%t Prime[ Select[ Range[1000], PrimeQ[ Prime[ # ]Prime[ # + 1] - 2] &]]

%t Select[Prime[Range[1000]],PrimeQ[# NextPrime[#]-2]&] (* _Harvey P. Dale_, Aug 05 2024 *)

%o (PARI) lista(nn) = {my(p=2); forprime(q=3, nn, if (isprime(p*q-2), print1(p, ", ")); p = q;);} \\ _Michel Marcus_, Sep 28 2019

%Y Cf. A123921, A124669.

%K nonn

%O 1,1

%A _Joseph L. Pe_, Jan 15 2002