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 A062227 #19 Oct 31 2019 01:24:23 %S A062227 3,9,11,17,23,25229 %N A062227 Numbers k such that the smoothly undulating palindromic number (91*10^k - 19)/99 is a prime. %C A062227 Prime versus probable prime status and proofs are given in the author's table. %C A062227 No further terms < 100000. - _Ray Chandler_, Aug 17 2011 %H A062227 Patrick De Geest, <a href="http://www.worldofnumbers.com/undulat.htm#supp919">SUPP Reference Table - 919</a> %H A062227 <a href="/index/Pri#pri_supp">Index entries for sequences related to smoothly undulating palindromic primes</a> %e A062227 k=23 -> (91*10^23 - 19)/99 = 91919191919191919191919. %Y A062227 Cf. A062209-A062232, A059758, A032758. %K A062227 nonn,base,more %O A062227 1,1 %A A062227 _Patrick De Geest_ and Hans Rosenthal (Hans.Rosenthal(AT)t-online.de), Jun 15 2001 %E A062227 Edited by _Ray Chandler_, Aug 17 2011