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A078011
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Expansion of (1-x)/(1-x-x^2+2*x^3).
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2
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1, 0, 1, -1, 0, -3, -1, -4, 1, -1, 8, 5, 15, 4, 9, -17, -16, -51, -33, -52, 17, 31, 152, 149, 239, 84, 25, -369, -512, -931, -705, -612, 545, 1343, 3112, 3365, 3791, 932, -2007, -8657, -12528, -17171, -12385, -4500, 17457, 37727, 64184, 66997, 55727, -5644, -83911, -201009, -273632, -306819
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OFFSET
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0,6
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LINKS
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FORMULA
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a(0)=1, a(1)=0, a(2)=1, a(n) = a(n-1) + a(n-2) - 2*a(n-3). - Harvey P. Dale, May 04 2013
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MATHEMATICA
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CoefficientList[Series[(1-x)/(1-x-x^2+2x^3), {x, 0, 60}], x] (* or *) LinearRecurrence[ {1, 1, -2}, {1, 0, 1}, 60] (* Harvey P. Dale, May 04 2013 *)
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PROG
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(PARI) my(x='x+O('x^60)); Vec((1-x)/(1-x-x^2+2*x^3)) \\ G. C. Greubel, Jun 28 2019
(Magma) R<x>:=PowerSeriesRing(Integers(), 60); Coefficients(R!( (1-x)/(1-x-x^2+2*x^3) )); // G. C. Greubel, Jun 28 2019
(Sage) ((1-x)/(1-x-x^2+2*x^3)).series(x, 60).coefficients(x, sparse=False) # G. C. Greubel, Jun 28 2019
(GAP) a:=[1, 0, 1];; for n in [4..60] do a[n]:=a[n-1]+a[n-2]-2*a[n-3]; od; a; # G. C. Greubel, Jun 28 2019
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CROSSREFS
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KEYWORD
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sign,easy
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AUTHOR
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STATUS
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approved
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