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 A253773 #29 Dec 11 2023 11:44:34 %S A253773 1,2,3,4,5,6,8,11,13,15,16,20,21,23,36,38,90,99,155,164,171,254,255, %T A253773 273,404,1386,1941,1970,2420,3759,5559,5776,6369,6429,22061,32330, %U A253773 81780,90248,162933,240920,504584 %N A253773 Numbers k such that 4^k + 15 is prime. %C A253773 Half of even terms of A057197. - _Michel Marcus_, Aug 28 2015 %e A253773 For k = 15, 4^15 + 15 = 1073741839 is prime. %t A253773 Select[Range[10000], PrimeQ[4^# + 15] &] %o A253773 (Magma) [n: n in [0..1300] | IsPrime(4^n+15)]; %o A253773 (PARI) is(n)=isprime(4^n + 15) \\ _Anders Hellström_, Aug 28 2015 %Y A253773 Cf. A057197, A237418, A253772 (similar sequence). %K A253773 nonn,more %O A253773 1,2 %A A253773 _Vincenzo Librandi_, Jan 12 2015 %E A253773 a(31)-a(39) from A057197 data by _Michel Marcus_, Aug 28 2015 %E A253773 a(40) derived from A057197 by _Robert Price_, Sep 18 2015 %E A253773 a(41) from A057197 data by _Elmo R. Oliveira_, Dec 11 2023