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 A364081 #12 Jan 05 2024 15:58:00 %S A364081 1,15,44,77,141,208,304,1169,3359,5050,22431,34935,92990 %N A364081 Numbers k such that (20^k + 1)^2 - 2 is prime. %C A364081 Such primes are sometimes called Kynea primes of base 20. %H A364081 Prime-Wiki, <a href="https://www.rieselprime.de/ziki/Carol-Kynea_prime">Carol-Kynea prime</a>. %H A364081 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Near-SquarePrime.html">Near-Square Prime</a>. %o A364081 (PARI) for(k=1,1200,ispseudoprime((20^k+1)^2-2)&&print1(k,", ")) %Y A364081 Cf. A091513 (b=2), A100902 (b=6), A100904 (b=10), A364077 (b=12), A100906 (b=14), A364079 (b=18), A100908 (b=22). %Y A364081 Cf. A364080. %K A364081 nonn,hard,more %O A364081 1,2 %A A364081 _Jeppe Stig Nielsen_, Jul 03 2023