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A158477 Primes p with property that Q(p) = p^32+2^32 is prime. 2

%I #24 Jul 08 2020 03:25:18

%S 29,59,101,103,109,181,199,379,769,881,919,977,1097,1213,1303,1583,

%T 2099,2113,2441,2521,2617,2777,3067,3739,4133,4289,4519,4931,5039,

%U 5113,5227,5417,5743,5783,6143,6373,6691,8053,8209,8287,8513,9109,9203,9689,9787,9923,9941

%N Primes p with property that Q(p) = p^32+2^32 is prime.

%C 1) Q=(p^16)^2+(2^16)^2 only for Q=4k+1 because of Fermat/Euler/Lagrange theorem concerning prime as sum of two squares.

%C 2) It is conjectured that sequence a(n) is infinite.

%C 3) Note the twin prime: a(3)=101, a(4)=103.

%C The next set of twins is a(101)=30557, a(102)=30559. - _Robert Israel_, Apr 05 2016

%D Richard E. Crandall, Carl Pomerance, Prime Numbers: A Computational Perspective, Springer 2001.

%D Leonard E. Dickson, History of the Theory of Numbers, Dover Pub. Inc., 2005.

%H Robert Israel, <a href="/A158477/b158477.txt">Table of n, a(n) for n = 1..10000</a>

%F n^32+2^32 and n to be prime.

%e p=3: 3^32+2^32=1853024483819137 = 1153 x 1607133116929 no prime;

%e also for following primes p=5, 7, 11, 13, 17, 19, 23: Q(p) no prime;

%e p=29: 29^32+2^32=62623297589448778360828428329074752313100292737 is prime => a(1)=29.

%p select(t -> isprime(t) and isprime(t^32 + 2^32), [seq(i,i=3..10000,2)]); # _Robert Israel_, Apr 05 2016

%t With[{c=2^32},Select[Prime[Range[1300]],PrimeQ[#^32+c]&]] (* _Harvey P. Dale_, May 04 2018 *)

%o (PARI) isA158477(n) = isprime(n) && isprime(n^32+4294967296) \\ _Michael B. Porter_, Dec 17 2009

%o (PARI) lista(nn) = forprime(p=3, nn, if(ispseudoprime(p^32+2^32), print1(p, ", "))); \\ _Altug Alkan_, Apr 05 2016

%Y Cf. A062324, A157764, A157950, A158361.

%K nonn

%O 1,1

%A Ulrich Krug (leuchtfeuer37(AT)gmx.de), Mar 20 2009

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Last modified April 25 06:42 EDT 2024. Contains 371964 sequences. (Running on oeis4.)