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 A261579 #17 Sep 08 2022 08:46:13 %S A261579 2,3,5,6,27,47,66,77,83,105,197,231,293,702,1692,3021,6270,6897,7733, %T A261579 14537,15797,21083,21276,28817,65430,111231,137405,141017,185225 %N A261579 Numbers m such that (4^m + 23) / 3 is prime. %C A261579 a(30) > 450,000. - _Robert Price_, Oct 04 2018 %e A261579 2 is in the sequence because (4^2 + 23)/3 = 13 is prime. %e A261579 3 is in the sequence because (4^3 + 23)/3 = 29 is prime. %t A261579 Select[Range[0, 5000], PrimeQ[(4^# + 23)/3] &] %o A261579 (Magma) [n: n in [0..1500] | IsPrime((4^n+23) div 3)]; %Y A261579 Cf. similar sequences listed in A261539. %K A261579 nonn,more %O A261579 1,1 %A A261579 _Vincenzo Librandi_, Aug 27 2015 %E A261579 a(17)-a(28) from _Robert Price_, Feb 01 2017 %E A261579 a(29) from _Robert Price_, Oct 04 2018