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A244452 Primes p such that p^2-2 and p^2+4 are also prime (i.e., initial members of prime triples (p, p^2-2, p^2+4)). 1

%I #25 Jan 19 2019 04:15:43

%S 3,5,7,13,37,47,103,233,293,313,607,677,743,1367,1447,2087,2543,3023,

%T 3803,3863,4093,4153,4373,4583,4643,4793,4957,5087,5153,5623,5683,

%U 5923,6287,7177,7247,7547,7817,8093,8527,9133,9403

%N Primes p such that p^2-2 and p^2+4 are also prime (i.e., initial members of prime triples (p, p^2-2, p^2+4)).

%C Intersection of A062326 and A062324.

%H Felix Fröhlich, <a href="/A244452/b244452.txt">Table of n, a(n) for n = 1..242507</a> (all terms up to 10^9)

%e 3 is in the sequence since it is the first member of the triple (3, 3^2-2, 3^2+4) and the resulting values in the triple (3, 7, 13) are all prime.

%t Select[Prime[Range[1200]],AllTrue[#^2+{4,-2},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Apr 28 2018 *)

%o (PARI) forprime(p=2, 10^4, if(isprime(p^2-2) && isprime(p^2+4), print1(p, ", ")))

%Y Cf. A022004, A073648, A098413.

%K nonn

%O 1,1

%A _Felix Fröhlich_, Jun 28 2014

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Last modified April 25 03:15 EDT 2024. Contains 371964 sequences. (Running on oeis4.)