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 A010859 #27 Dec 27 2021 21:49:52
%S A010859 20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,
%T A010859 20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,
%U A010859 20,20,20,20,20,20,20,20
%N A010859 Constant sequence: a(n) = 20.
%H A010859 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>
%H A010859 <a href="/index/Di#divseq">Index to divisibility sequences</a>
%H A010859 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1).
%F A010859 G.f.: 20/(1-x); e.g.f.: 20*e^x. - _Vincenzo Librandi_, Jan 22 2012
%t A010859 PadRight[{},100,20] (* _Harvey P. Dale_, Jul 07 2017 *)
%K A010859 nonn,easy
%O A010859 0,1
%A A010859 _N. J. A. Sloane_