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%I #31 Dec 12 2023 09:25:21
%S 1,1,-1,1,-1,1,1,-1,1,-1,1,1,-1,1,-1,1,1,-1,1,-1,1,1,-1,1,-1,1,1,-1,1,
%T -1,1,1,-1,1,-1,1,1,-1,1,-1,1,1,-1,1,-1,1,1,-1,1,-1,1,1,-1,1,-1,1,1,
%U -1,1,-1,1,1,-1,1,-1,1,1,-1,1,-1
%N Period 5: repeat [1, 1, -1, 1, -1].
%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,1).
%F G.f.: (-1-x+x^2-x^3+x^4)/(x-1)/(1+x+x^2+x^3+x^4). - _R. J. Mathar_, Nov 14 2007
%F a(0)=1, a(1)=1, a(2)=-1, a(3)=1, a(4)=-1, a(n)=a(n-5). - _Harvey P. Dale_, Jul 05 2013
%F a(n) = (1 - 4*(cos(4*(n-4)*Pi/5) + cos(2*(n-2)*Pi/5) + cos(4*(n-2)*Pi/5) + cos(2*(n+1)*Pi/5)))/5. - _Wesley Ivan Hurt_, Sep 27 2018
%t PadRight[{},120,{1,1,-1,1,-1}] (* or *) LinearRecurrence[{0,0,0,0,1},{1,1,-1,1,-1},120] (* _Harvey P. Dale_, Jul 05 2013 *)
%o (PARI) Vec((1+x-x^2+x^3-x^4)/(1-x)/(1+x+x^2+x^3+x^4)+O(x^99)) \\ _Charles R Greathouse IV_, Jun 13 2013
%K sign,easy,less
%O 0,1
%A _Paul Curtz_, Aug 26 2007
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