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 A227174 #12 Nov 27 2020 01:10:14 %S A227174 23,41,43,151,2927,6133 %N A227174 Numbers n such that (140^n + 139^n)/279 is prime. %C A227174 All terms are prime. %C A227174 a(7) > 10^4. %C A227174 a(7) > 43400. - _Lucas A. Brown_, Nov 26 2020 %o A227174 (PARI) is(n)=ispseudoprime((140^n+139^n)/279) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A227174 Cf. A000978, A057469, A128066, A128335, A128336, A187805, A181141, A187819, A217095. %K A227174 hard,nonn,more %O A227174 1,1 %A A227174 _Jean-Louis Charton_, Jul 03 2013