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 A291311 #33 Jun 25 2023 03:41:40
%S A291311 1,2,3,5,9,16,27,45,75,125,207,341,560,918,1502,2453,4000,6515,10601,
%T A291311 17235,28000,45461,73773,119665,194033,314519,509685,825768,1337612,
%U A291311 2166360,3508085,5680122,9196043,14886981,24097953,39005540,63131935,102176733,165362855,267614381
%N A291311 Expansion of (1-x^2)/((1-x-x^2)*(1-x-x^4)).
%H A291311 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (2,0,-1,1,-1,-1).
%F A291311 G.f.: (1-x^2)/((1-x-x^2)*(1-x-x^4)).
%t A291311 LinearRecurrence[{2,0,-1,1,-1,-1},{1,2,3,5,9,16},40] (* _Harvey P. Dale_, Apr 18 2018 *)
%o A291311 (PARI) my(x='x+O('x^50)); Vec((1 - x^2)/((1-x-x^2)*(1-x-x^4))) \\ _Michel Marcus_, Jun 25 2023
%Y A291311 Cf. A131298.
%K A291311 nonn,easy
%O A291311 0,2
%A A291311 _Roger L. Bagula_, Aug 21 2017