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 A131736 #26 Jun 10 2025 01:09:59
%S A131736 0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1,-1,-1,
%T A131736 1,0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1,-1,
%U A131736 -1,1,0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1,-1,-1,1,0,0,1
%N A131736 Period 6: repeat [0, 0, 1, -1, -1, 1].
%H A131736 Matthew House, <a href="/A131736/b131736.txt">Table of n, a(n) for n = 0..10000</a>
%H A131736 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,-1,0,-1).
%F A131736 From _Matthew House_, Jan 15 2017: (Start)
%F A131736 G.f.: x^2*(1-x)/(1+x^2+x^4).
%F A131736 a(n) = -a(n-2) - a(n-4) for n > 3. (End)
%F A131736 a(n) = sin(n*Pi/6) * (3*sin(n*Pi/2) - 2*sqrt(3)*cos(n*Pi/6) - 3*sqrt(3)*cos(n*Pi/2)) / 3. - _Wesley Ivan Hurt_, Apr 26 2020
%F A131736 From _Nicolas Bělohoubek_, Jun 05 2025: (Start)
%F A131736 a(n) = A022003(n) - A131532(n+1).
%F A131736 a(n) = a(n-6) for n > 5. (End)
%t A131736 PadRight[{}, 100, {0, 0, 1, -1, -1, 1}] (* _Wesley Ivan Hurt_, Jan 15 2017 *)
%Y A131736 Cf. A022003, A131532.
%K A131736 sign,easy
%O A131736 0,1
%A A131736 _Paul Curtz_, Sep 19 2007
%E A131736 Title edited by _Matthew House_, Jan 15 2017