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%I #13 Sep 08 2022 08:45:08
%S 1,0,-2,2,4,-8,-4,24,-8,-56,64,96,-240,-64,672,-352,-1472,2048,2240,
%T -7040,-384,18560,-13312,-37888,63744,49152,-203264,29184,504832,
%U -464896,-951296,1939456,972800,-5781504,1933312,13508608,-15429632,-23150592,57876480,15441920,-162054144
%N Expansion of 1/(1+2*x^2-2*x^3).
%H G. C. Greubel, <a href="/A077964/b077964.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (0,-2,2).
%F a(n) = (-1)^n * A077968(n). - _G. C. Greubel_, Jun 24 2019
%t LinearRecurrence[{0,-2,2}, {1,0,-2}, 50] (* or *) CoefficientList[Series[ 1/(1+2*x^2-2*x^3), {x,0,50}], x] (* _G. C. Greubel_, Jun 24 2019 *)
%o (PARI) Vec(1/(1+2*x^2-2*x^3)+O(x^50)) \\ _Charles R Greathouse IV_, Sep 26 2012
%o (Magma) R<x>:=PowerSeriesRing(Integers(), 50); Coefficients(R!( 1/(1+2*x^2-2*x^3) )); // _G. C. Greubel_, Jun 24 2019
%o (Sage) (1/(1+2*x^2-2*x^3)).series(x, 50).coefficients(x, sparse=False) # _G. C. Greubel_, Jun 24 2019
%o (GAP) a:=[1,0,-2];; for n in [4..50] do a[n]:=2*(-a[n-2]+a[n-3]); od; a; # _G. C. Greubel_, Jun 24 2019
%Y Cf. A077968, A078037.
%K sign,easy
%O 0,3
%A _N. J. A. Sloane_, Nov 17 2002
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