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%I #19 Jun 11 2021 00:10:16
%S 3,5,17,397,409,643,1783,2617,4583,8783
%N Numbers k such that (6^k + 5^k)/11 is prime.
%C All terms are primes.
%C No other terms less than 100000. - _Robert Price_, May 11 2012
%t k=6; Do[p=Prime[n]; f=(k^p+5^p)/(k+5); If[ PrimeQ[f], Print[p] ], {n,1,100}]
%o (PARI) forprime(p=3,1e4,if(ispseudoprime((6^p+5^p)/11),print1(p", "))) \\ _Charles R Greathouse IV_, Jul 16 2011
%Y Cf. A057171, A082387, A122853, A128335, A128337, A128338, A128339, A128340, A128341, A128342, A128343, A004061, A082182, A121877, A059802, A062572, A128344, A128345, A128346, A128347, A128348, A128349, A128350, A128351, A128352, A128353, A128354.
%K hard,more,nonn
%O 1,1
%A _Alexander Adamchuk_, Feb 27 2007
%E a(7)-a(9) from _Alexander Adamchuk_, May 04 2010
%E One more term (8783) added (unknown discoverer) corresponding to a probable prime with 6834 digits by _Jean-Louis Charton_, Oct 06 2010
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