# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a128352 Showing 1-1 of 1 %I A128352 #12 Jun 11 2021 08:45:23 %S A128352 5,7,17,23,43,71,239,733,1097 %N A128352 Numbers k such that (17^k - 5^k)/12 is prime. %C A128352 All terms are primes. %C A128352 a(10) > 10^5. - _Robert Price_, Jun 11 2013 %t A128352 k=17; Do[p=Prime[n]; f=(k^p-5^p)/(k-5); If[ PrimeQ[f], Print[p] ], {n,1,100}] %o A128352 (PARI) is(n)=isprime((17^n-5^n)/12) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A128352 Cf. A062572, A128344, A128345, A128346, A128347, A128348, A128349, A128350, A128351, A128353, A128354. %Y A128352 Cf. A004061, A082182, A121877, A059802. %Y A128352 Cf. A057171, A082387, A122853, A128335, A128336, A128337, A128338, A128339, A128340, A128341, A128342. %K A128352 nonn,hard,more %O A128352 1,1 %A A128352 _Alexander Adamchuk_, Feb 27 2007 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE