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 A227172 #14 Jun 24 2025 10:42:10 %S A227172 13,31,631,5279,36781 %N A227172 Numbers k such that (48^k + 47^k)/95 is prime. %C A227172 All terms are prime. %C A227172 a(5) > 10^4. %o A227172 (PARI) is(n)=ispseudoprime((48^n+47^n)/95) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A227172 Cf. A000978, A057469, A128066, A128335, A128336, A187805, A181141, A187819, A217095. %K A227172 hard,nonn,more %O A227172 1,1 %A A227172 _Jean-Louis Charton_, Jul 03 2013 %E A227172 a(5) from _Michael S. Branicky_, Jun 23 2025