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 A293995 #9 Aug 08 2021 15:01:13
%S A293995 1,1,3,15,35,103,343,979,2915,8935,26559,79499,239547,717455,2151095,
%T A293995 6459027,19371507,58106071,174349295,523022555,1569013931,4707208351,
%U A293995 14121515303,42364215075,127093528675,381280144743,1143838446943,3431519977579,10294558387995
%N A293995 Number of linear chord diagrams having n chords and no chord length larger than three.
%H A293995 Alois P. Heinz, <a href="/A293995/b293995.txt">Table of n, a(n) for n = 0..1000</a>
%H A293995 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (2,1,8,-6)
%F A293995 G.f.: -(x-1)/((3*x-1)*(2*x^3-2*x^2-x-1)).
%t A293995 LinearRecurrence[{2,1,8,-6},{1,1,3,15},30] (* _Harvey P. Dale_, Aug 08 2021 *)
%Y A293995 Column k=3 of A293960.
%K A293995 nonn,easy
%O A293995 0,3
%A A293995 _Alois P. Heinz_, Oct 21 2017