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 A128032 #15 Nov 01 2018 21:22:24 %S A128032 73,271,421,2711 %N A128032 Numbers k such that (19^k - 3^k)/16 is prime. %C A128032 All terms are primes. %C A128032 No other terms <= 10^5. - _Robert Price_, Aug 27 2011 %t A128032 k=16; Select[ Prime[ Range[1,200] ], PrimeQ[ ((k+3)^# - 3^#)/k ]& ] %o A128032 (PARI) is(n)=isprime((19^n-3^n)/16) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A128032 Cf. A028491, A057468, A059801, A121877, A128024, A128025, A128026, A128027, A128028, A128029, A128030, A128031. %K A128032 hard,more,nonn %O A128032 1,1 %A A128032 _Alexander Adamchuk_, Feb 11 2007 %E A128032 2711 from _Farideh Firoozbakht_, Apr 07 2007