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 A089521 #5 Mar 30 2012 17:27:41 %S A089521 9999,99999,990099,999999,9901099,9905099,9993999,9996999,9997999, %T A089521 9998999,9999999,99999999,990959099,990969099,999010999,999020999, %U A089521 999030999,999040999,999070999,999929999,999939999,999969999,999989999 %N A089521 Terms of A088753 that are not terms of A063048. %C A089521 Palindromes in A088753; palindromes for which the Reverse and Add! process does not lead to another palindrome. The numbers were extracted from W. VanLandingham's list of Lychrel numbers. %H A089521 W. VanLandingham, <a href="http://www.p196.org/">196 and Other Lychrel Numbers</a> %H A089521 <a href="/index/Res#RAA">Index entries for sequences related to Reverse and Add!</a> %Y A089521 Cf. A088753, A063048, A089522, A089694. %K A089521 nonn,base %O A089521 1,1 %A A089521 _Klaus Brockhaus_, Nov 10 2003