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 A031253 #11 Jan 15 2024 18:53:28
%S A031253 1,3,1,0,1,2,1,4,2,1,2,3,3,0,3,2,3,4,4,1,4,3,1,0,0,1,0,2,1,0,4,1,1,1,
%T A031253 1,1,3,1,2,0,1,2,2,1,2,4,1,3,1,1,3,3,1,4,0,1,4,2,1,4,4,2,0,1,2,0,3,2,
%U A031253 1,0,2,1,2,2,1,4,2,2,1,2,2,3,2,3,0,2,3,2,2,3
%N A031253 Write 2n-1 in base 5 and juxtapose.
%H A031253 Robert Israel, <a href="/A031253/b031253.txt">Table of n, a(n) for n = 1..10000</a>
%p A031253 map(op,[seq(ListTools:-Reverse(convert(2*n-1,base,5)),n=1..100)]); # _Robert Israel_, Sep 20 2019
%t A031253 Table[IntegerDigits[2n-1,5],{n,60}]//Flatten (* _Harvey P. Dale_, Jan 14 2024 *)
%K A031253 nonn,base
%O A031253 1,2
%A A031253 _Clark Kimberling_