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 A373568 #16 Jun 12 2024 11:40:32
%S A373568 1,5,10,30,85,246,707,2037,5864,16886,48620,139997,403104,1160693,
%T A373568 3342081,9623140,27708726,79784098,229729153,661478734,1904652103,
%U A373568 5484227157,15791202736,45468956106,130922641160,376976720745,1085461206128,3125460977225,8999406210929
%N A373568 Expansion of x - 1/(x - 1/(x - 1/(x - 1/(x + 1)))).
%H A373568 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (2,3,-1,-1).
%F A373568 a(n) = [x^n] (x^5 + x^4 - 4*x^3 - 3*x^2 + 3*x + 1)/(x^4 + x^3 - 3*x^2 - 2*x + 1).
%t A373568 CoefficientList[Series[x - 1/(x - 1/(x - 1/(x - 1/(x + 1)))), {x, 0, 28}], x] (* _Michael De Vlieger_, Jun 10 2024 *)
%Y A373568 Essentially the same as A006357.
%K A373568 nonn,easy
%O A373568 0,2
%A A373568 _Peter Luschny_, Jun 10 2024