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 A309527 #36 Mar 15 2023 06:47:59 %S A309527 1,2,3,5,8,10,19,27,79,198,565,787,2183,3811,4748,6210,7887,8965, %T A309527 13303,20125,23433,28797 %N A309527 Numbers k such that 6^k + 17 is prime. %C A309527 a(20) > 14000. - _Daniel Starodubtsev_, Apr 17 2020 %e A309527 3 is in the sequence because 6^3 + 17 = 233, which is prime. %o A309527 (PARI) lista(nn)=for(k=0,nn,if(ispseudoprime(6^k+17),print1(k", "))) %Y A309527 Cf. A013600, A013607, A059614, A145106, A182331, A217351, A217352. %K A309527 nonn,more,hard,less %O A309527 1,2 %A A309527 _Daniel Starodubtsev_, Aug 06 2019 %E A309527 a(17)-a(18) from _Daniel Starodubtsev_, Mar 16 2020 %E A309527 a(19) from _Daniel Starodubtsev_, Apr 17 2020 %E A309527 a(20)-a(22) from _Michael S. Branicky_, Mar 14 2023