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A078017
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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, -3, -2, 3, 11, 12, -5, -39, -58, -9, 127, 252, 143, -363, -1010, -933, 803, 3756, 4819, -543, -12874, -21969, -8009, 39708, 91655, 67965, -103106, -354381, -387205, 173388, 1269355, 1870377, 254246, -4154841, -8149841, -4503492, 11956031, 32759205, 29810158, -26861109
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OFFSET
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0,4
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LINKS
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FORMULA
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G.f.: (1-x)/(1-x+x^2+2*x^3).
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MATHEMATICA
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LinearRecurrence[{1, -1, -2}, {1, 0, -1}, 50] (* or *) CoefficientList[ Series[(1-x)/(1-x+x^2+2*x^3), {x, 0, 50}], x] (* G. C. Greubel, Jun 29 2019 *)
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PROG
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(Magma) R<x>:=PowerSeriesRing(Integers(), 50); Coefficients(R!( (1-x)/(1-x+x^2+2*x^3) )); // G. C. Greubel, Jun 29 2019
(Sage) ((1-x)/(1-x+x^2+2*x^3)).series(x, 50).coefficients(x, sparse=False) # G. C. Greubel, Jun 29 2019
(GAP) a:=[1, 0, -1];; for n in [4..50] do a[n]:=a[n-1]-a[n-2]-2*a[n-3]; od; a; # G. C. Greubel, Jun 29 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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