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 A128030 #17 Mar 11 2023 23:06:50 %S A128030 2,3,31,467,1747,29683 %N A128030 Numbers k such that (16^k - 3^k)/13 is prime. %C A128030 All terms are primes. %C A128030 No other terms < 100000. %t A128030 k=13; Select[ Prime[ Range[1,200] ], PrimeQ[ ((k+3)^# - 3^#)/k ]& ] %o A128030 (PARI) is(n)=isprime((16^n-3^n)/13) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A128030 Cf. A028491 = numbers n such that (3^n - 1)/2 is prime. Cf. A057468 = numbers n such that 3^n - 2^n is prime. Cf. A059801 = numbers n such that 4^n - 3^n is prime. Cf. A121877 = numbers n such that (5^n - 3^n)/2 is a prime. Cf. A128024, A128025, A128026, A128027, A128028, A128029, A128031, A128032. %K A128030 hard,more,nonn %O A128030 1,1 %A A128030 _Alexander Adamchuk_, Feb 11 2007 %E A128030 1747 from _Farideh Firoozbakht_, Apr 08 2007 %E A128030 a(6)=29683 from _Robert Price_, Sep 13 2011