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 A309140 #19 Nov 04 2024 18:33:04 %S A309140 3,5,6,9,15,87,2323,13733 %N A309140 Numbers k such that k^(k + 1) + k - 1 is prime. %C A309140 a(7) > 2000. %C A309140 a(8) > 5000. - _Daniel Suteu_, Jul 25 2019 %C A309140 a(8) > 10000. - _Michael S. Branicky_, Apr 01 2023 %o A309140 (PARI) for(n=1,100,my(x=n^(n+1)+n-1);if(isprime(x),print1(n,", "))) %Y A309140 Cf. A155499, A268987. %K A309140 nonn,more,hard %O A309140 1,1 %A A309140 _Hugo Pfoertner_, Jul 23 2019 %E A309140 a(7) from _Daniel Suteu_, Jul 25 2019 %E A309140 a(8) from _Michael S. Branicky_, Nov 04 2024