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 A224507 #12 Jun 06 2017 14:33:21 %S A224507 5,7,113,193,211,701,797,907,4153 %N A224507 Numbers n such that (17^n + 2^n)/19 is prime. %C A224507 All terms are prime. %C A224507 a(10) > 10^5. %t A224507 Select[Prime[Range[1, 100000]], PrimeQ[(17^# + 2^#)/19]&] %o A224507 (PARI) is(n)=ispseudoprime((17^n+2^n)/19) \\ _Charles R Greathouse IV_, Jun 06 2017 %Y A224507 Cf. A057183, A125957, A222265, A225191, A227046. %K A224507 nonn,hard,more %O A224507 1,1 %A A224507 _Robert Price_, Jul 20 2013