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 A023403 #13 Jan 27 2022 22:45:26 %S A023403 4,4,5,4,4,4,4,5,4,5,4,5,5,5,5,4,4,5,4,5,4,5,5,4,5,5,4,5,4,5,5,4,4,4, %T A023403 4,5,4,5,4,5,4,4,4,5,5,5,5,4,4,5,5,5,4,5,4,4,5,5,5,5,4,5,5,4,5,5,4,5, %U A023403 5,5,5,5,4,4,5,4,5,5,5,5,5,4,4,5,5,4,4,5,5,4,5,4,5,4,5,4,5,4,5,4,5,4,4,5,4,5,5,4 %N A023403 If any power of 2 ends with k 4's and 5's, they must be the first k terms of this sequence in reverse order. %H A023403 Ray Chandler, <a href="/A023403/b023403.txt">Table of n, a(n) for n = 1..10000</a> %K A023403 nonn,base %O A023403 1,1 %A A023403 _David W. Wilson_