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 A165983 #26 Dec 12 2023 07:44:22
%S A165983 1,1,1,2,1,1,1,2,1,1,1,4,1,1,1,4,1,1,1,2,1,1,1,2,1,1,1,4,1,1,1,4,1,1,
%T A165983 1,2,1,1,1,2,1,1,1,4,1,1,1,4,1,1,1,2,1,1,1,2,1,1,1,4,1,1,1,4,1,1,1,2,
%U A165983 1,1,1,2,1,1,1,4,1,1,1,4,1,1,1,2,1,1,1,2,1,1,1,4,1,1,1,4,1,1,1,2,1,1,1,2,1
%N A165983 Period 16: repeat 1,1,1,2,1,1,1,2,1,1,1,4,1,1,1,4.
%C A165983 The numerator of the reduced fraction A061037(n+3)/A061041(2n+6).
%H A165983 <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,1,0,0,0,-1,0,0,0,1).
%F A165983 a(n) = a(n-4) - a(n-8) + a(n-12). - _R. J. Mathar_, Dec 17 2010
%F A165983 G.f.: ( -1 - x - x^2 - 2*x^3 - x^8 - x^9 - x^10 - 4*x^11 ) / ( (x-1)*(1+x)*(1+x^2)*(x^8+1) ). - _R. J. Mathar_, Dec 17 2010
%F A165983 a(4n) = a(4n+1) = a(4n+2) = 1. a(4n+3) = A165207(n).
%t A165983 LinearRecurrence[{0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, 1}, {1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 4}, 50] (* _G. C. Greubel_, Apr 20 2016 *)
%o A165983 (PARI) x='x+O('x^50); Vec(( -1-x-x^2-2*x^3-x^8-x^9-x^10-4*x^11 )/((x-1)*(1+x)*(1+x^2)*(x^8+1))) \\ _G. C. Greubel_, Sep 20 2018
%o A165983 (Magma) m:=50; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(( -1-x-x^2-2*x^3-x^8-x^9-x^10-4*x^11 )/((x-1)*(1+x)*(1+x^2)*(x^8+1)))); // _G. C. Greubel_, Sep 20 2018
%Y A165983 Cf. A064038.
%K A165983 nonn,easy,less
%O A165983 0,4
%A A165983 _Paul Curtz_, Oct 03 2009