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 A093401 #19 Jul 08 2021 05:54:13 %S A093401 29,229,22229,22222222222229 %N A093401 Primes of the form 20*R_k + 9, where R_k is the repunit (A002275) of length k. %C A093401 a(5) has 176 digits, a(6) has 416 digits. - _Vincenzo Librandi_, Dec 10 2010; _Bruno Berselli_, Jul 17 2012 %H A093401 Makoto Kamada, <a href="https://stdkmd.net/nrr/2/22229.htm#prime">Prime numbers of the form 22...229</a>. %H A093401 <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a> %Y A093401 Cf. A002275, A056678 (corresponding k), A099410. %K A093401 nonn %O A093401 1,1 %A A093401 _Rick L. Shepherd_, Mar 28 2004