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 A370657 #13 Mar 02 2024 06:32:52 %S A370657 34,48,8578,18960 %N A370657 Numbers k such that A226199(k) = 7^k + k is prime. %C A370657 If it exists, a(5) > 268000. - _Karl-Heinz Hofmann_, Mar 02 2024 %o A370657 (PARI) is(n) = ispseudoprime(7^n+n) %Y A370657 Cf. A058828, A221909, A226199, A370660. %K A370657 nonn,hard,more %O A370657 1,1 %A A370657 _Hugo Pfoertner_, Feb 24 2024