# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a128341 Showing 1-1 of 1 %I A128341 #14 Jun 11 2021 00:17:57 %S A128341 3,5,13,347,977,1091,4861,4967,34679 %N A128341 Numbers k such that (12^k + 5^k)/17 is prime. %C A128341 All terms are primes. %C A128341 a(10) > 10^5. - _Robert Price_, May 05 2013 %t A128341 k=12; Do[p=Prime[n]; f=(k^p+5^p)/(k+5); If[ PrimeQ[f], Print[p] ], {n,1,100}] %t A128341 Select[Range[1100],PrimeQ[(12^#+5^#)/17]&] (* _Harvey P. Dale_, Jul 24 2012 *) %o A128341 (PARI) is(n)=isprime((12^n+5^n)/17) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A128341 Cf. A057171, A082387, A122853, A128335, A128336, A128337, A128338, A128339, A128340, A128342, A128343. %Y A128341 Cf. A004061, A082182, A121877, A059802. %Y A128341 Cf. A062572, A128344, A128345, A128346, A128347, A128348, A128349, A128350, A128351, A128352, A128353, A128354. %K A128341 hard,more,nonn %O A128341 1,1 %A A128341 _Alexander Adamchuk_, Feb 27 2007 %E A128341 Two more terms (a(7) and a(8)) from _Harvey P. Dale_, Jul 24 2012 %E A128341 a(9) from _Robert Price_, May 05 2013 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE