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 A023398 #13 Jan 27 2022 22:44:25 %S A023398 2,5,5,5,5,2,5,5,2,2,2,2,5,5,2,2,2,2,2,5,5,5,5,2,5,5,5,2,2,5,5,5,5,5, %T A023398 5,5,5,5,5,2,5,5,2,5,2,5,2,2,5,2,2,2,2,5,5,5,5,5,2,2,5,5,2,5,2,5,5,5, %U A023398 2,5,2,2,2,5,2,2,2,5,5,2,2,2,5,2,5,2,5,5,2,2,5,5,2,5,2,2,5,2,2,2,2,5,2,5,5,2,5,2 %N A023398 If any power of 2 ends with k 2's and 5's, they must be the first k terms of this sequence in reverse order. %H A023398 Ray Chandler, <a href="/A023398/b023398.txt">Table of n, a(n) for n = 1..10000</a> %K A023398 nonn,base %O A023398 1,1 %A A023398 _David W. Wilson_