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 A062220 #17 Aug 11 2024 14:41:34 %S A062220 3,9,15,17,21,57,4233,4335,13221,26447,29897,91997 %N A062220 Numbers k such that the smoothly undulating palindromic number (38*10^k - 83)/99 is a prime. %C A062220 Prime versus probable prime status and proofs are given in the author's table. %C A062220 No further terms < 100000. - _Ray Chandler_, Aug 17 2011 %H A062220 P. De Geest, <a href="https://www.worldofnumbers.com/undulat.htm#supp383">SUPP Reference Table - 383</a> %H A062220 <a href="/index/Pri#pri_supp">Index entries for sequences related to smoothly undulating palindromic primes</a> %e A062220 k=21 -> (38*10^21 - 83)/99 = 383838383838383838383. %Y A062220 Cf. A062209-A062232, A059758, A032758. %K A062220 nonn,base %O A062220 1,1 %A A062220 _Patrick De Geest_ and Hans Rosenthal (Hans.Rosenthal(AT)t-online.de), Jun 15 2001 %E A062220 a(12)=91997 from _Ray Chandler_, Jul 29 2011 %E A062220 Edited by _Ray Chandler_, Aug 17 2011