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 A298509 #13 Jan 22 2018 16:01:50 %S A298509 99,99,99,99,97,2,97,2,89,8,91,8,509,2,88,2,88,2,88,2,88,2,88,2,50, %T A298509 497,2,88,2,88,2,88,2,88,2,88,2,50,497,2,88,2,88,2,88,2,88,2,88,2 %N A298509 First differences of A023108. %C A298509 It appears that this sequence has a very regular pattern, as shown by the attached .png graphical visualization. %H A298509 Alessandro Polcini, <a href="/A298509/b298509.txt">Table of n, a(n) for n = 1..100000</a> %H A298509 Alessandro Polcini, <a href="/A298509/a298509.png">Lychrel steps, graphically visualized in a 1000x1000 grid</a> %Y A298509 Cf. A023108. %K A298509 nonn,base %O A298509 1,1 %A A298509 _Alessandro Polcini_, Jan 20 2018