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A131554
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Period 5: repeat [1, 1, -1, 1, -1].
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0
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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, -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, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1
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OFFSET
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0,1
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LINKS
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FORMULA
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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
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
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
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MATHEMATICA
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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 *)
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PROG
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CROSSREFS
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KEYWORD
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sign,easy,less
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AUTHOR
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STATUS
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approved
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