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 A224501 #7 Jun 06 2017 14:33:20 %S A224501 7,53,67,71,443,26497 %N A224501 Numbers n such that (11^n + 4^n)/15 is prime. %C A224501 All terms are prime. %C A224501 a(7) > 10^5. %t A224501 Select[ Prime[ Range[1, 100000] ], PrimeQ[ (11^# + 4^#)/15 ]& ] %o A224501 (PARI) is(n)=ispseudoprime((11^n+4^n)/15) \\ _Charles R Greathouse IV_, Jun 06 2017 %Y A224501 Cf. A057178, A128341, A181141, A187819, A217095. %K A224501 hard,nonn,more %O A224501 1,1 %A A224501 _Robert Price_, Apr 08 2013