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 A309328 #17 Mar 28 2023 03:48:36 %S A309328 0,1,3,7,9,19,27,33,147,639,12243,41427,44287,44449 %N A309328 Numbers k such that 2^k + k + 2 is prime. %C A309328 If it exists, a(12) > 30000. %C A309328 a(15) > 100000. - _Michael S. Branicky_, Mar 27 2023 %t A309328 Select[Range[0, 2047], PrimeQ[2^# + # + 2] &] (* _Alonso del Arte_, Jul 23 2019 *) %o A309328 (PARI) for(n=0,15000,my(x=2^n+n+2); if(ispseudoprime(x), print1(n,", "))) %Y A309328 A052968, A187733. %K A309328 nonn,more,hard %O A309328 1,3 %A A309328 _Hugo Pfoertner_, Jul 23 2019 %E A309328 a(12)-a(14) from _Michael S. Branicky_, Mar 26 2023