This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A128349 #14 Jun 11 2021 04:58:35
%S A128349 5,19,71,197,659,22079,61949
%N A128349 Numbers k such that (13^k - 5^k)/8 is prime.
%C A128349 All terms are primes.
%C A128349 a(8) > 10^5. - _Robert Price_, Mar 05 2013
%t A128349 k=13; Do[p=Prime[n]; f=(k^p-5^p)/(k-5); If[ PrimeQ[f], Print[p] ], {n,1,100}]
%o A128349 (PARI) is(n)=isprime((13^n-5^n)/8) \\ _Charles R Greathouse IV_, Feb 17 2017
%Y A128349 Cf. A062572, A128344, A128345, A128346, A128347, A128348, A128350, A128351, A128352, A128353, A128354.
%Y A128349 Cf. A004061, A082182, A121877, A059802.
%Y A128349 Cf. A057171, A082387, A122853, A128335, A128336, A128337, A128338, A128339, A128340, A128341, A128342.
%K A128349 hard,more,nonn
%O A128349 1,1
%A A128349 _Alexander Adamchuk_, Feb 27 2007
%E A128349 a(6)-a(7) from _Robert Price_, Mar 05 2013