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 A229542 #15 Jun 05 2021 16:45:15 %S A229542 11,19,79,631,1787,2011,2381,20219,49523 %N A229542 Numbers n such that (19^n - 2^n)/17 is prime. %C A229542 All terms are primes. %C A229542 a(10) > 2*10^5. %t A229542 Select[ Prime[ Range[1, 100000] ], PrimeQ[ (19^# - 2^#)/17 ]& ] %o A229542 (PARI) is(n)=ispseudoprime((19^n-2^n)/17) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A229542 Cf. A128032, A225955, A225807, A006035. %K A229542 nonn,hard,more %O A229542 1,1 %A A229542 _Robert Price_, Sep 25 2013