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 A217355 #42 Oct 31 2024 11:23:35 %S A217355 1,47,91,64655 %N A217355 Numbers k such that 8^k + 5 is prime. %C A217355 All terms are 1/3 of the terms of A059242 that are multiples of 3. %C A217355 No more terms <= 10^5. - _Tyler NeSmith_ %t A217355 Select[Range[1000], PrimeQ[8^# + 5] &] %o A217355 (Magma) [n: n in [0..1000] | IsPrime(8^n + 5)]; %o A217355 (PARI) is(n)=ispseudoprime(8^n+5) \\ _Charles R Greathouse IV_, Feb 20 2017 %Y A217355 Cf. A059242, A217354. %K A217355 nonn,hard,more %O A217355 1,2 %A A217355 _Vincenzo Librandi_, Oct 02 2012 %E A217355 a(4) from _Tyler NeSmith_, Jan 19 2021