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 A129221 #8 Feb 16 2025 08:33:05 %S A129221 4,14,194,4870,3953,5970,1857,36,1294,3470,128,0 %N A129221 Residues of the Lucas - Lehmer primality test for M(13) = 8191. %C A129221 Since a(11) = 0, M(13) = 8191 is prime. %H A129221 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Lucas-LehmerTest.html">Lucas Lehmer Test</a>. %H A129221 Wikipedia, <a href="https://en.wikipedia.org/wiki/Lucas-Lehmer_primality_test">Lucas Lehmer Primality Test</a>. %F A129221 a(0) = 4 a(n) = a(n-1)^2 mod 2^p-1 Last term: a(p-2) %e A129221 a(11)= 128^2 - 2 mod 8191 = 16382 mod 8191 = 0 %Y A129221 Cf. A095847, A003010, A129219, A129220, A129222, A129223, A129224, A129225, A129226, A001348. %K A129221 fini,full,nonn %O A129221 0,1 %A A129221 _Sergio Pimentel_, Apr 04 2007