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 A217135 #13 Nov 09 2023 11:37:00 %S A217135 3,4,7,8,14,20,22,62,139,254,272,430,907,1906,2278,2827,3598,6812, %T A217135 15266,20915,26180,26342,27022,48275,65186,69247,86647 %N A217135 Numbers k such that 3^k - 8 is prime. %C A217135 a(28) > 2*10^5. - _Robert Price_, Sep 02 2013 %t A217135 Select[Range[2, 5000], PrimeQ[3^# - 8] &] %o A217135 (PARI) for(n=2, 5*10^3, if(isprime(3^n-8), print1(n", "))) %Y A217135 Cf. A014224, A051783, A058958, A058959. %K A217135 nonn %O A217135 1,1 %A A217135 _Vincenzo Librandi_, Oct 01 2012 %E A217135 a(18)-a(27) from _Robert Price_, Sep 02 2013