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%I #9 Sep 08 2022 08:45:08
%S 1,0,-2,-1,4,4,-7,-12,10,31,-8,-72,-15,152,102,-289,-356,476,1001,
%T -596,-2478,191,5552,2096,-11295,-9744,20494,30783,-31244,-82060,
%U 31705,195364,18650,-422433,-232664,826216,887761,-1419768,-2601738,1951775,6623244,-1301812,-15198263,-4019620
%N Expansion of 1/(1+2*x^2+x^3).
%H G. C. Greubel, <a href="/A077967/b077967.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,-1).
%F a(n) = (-1)^n * A077965(n). - _G. C. Greubel_, Jun 24 2019
%t CoefficientList[Series[1/(1+2x^2+x^3),{x,0,50}],x] (* or *) LinearRecurrence[ {0,-2,-1},{1,0,-2},50] (* _Harvey P. Dale_, Nov 10 2017 *)
%o (PARI) my(x='x+O('x^50)); Vec(1/(1+2*x^2+x^3)) \\ _G. C. Greubel_, Jun 24 2019
%o (Magma) R<x>:=PowerSeriesRing(Integers(), 50); Coefficients(R!( 1/(1+2*x^2+x^3) )); // _G. C. Greubel_, Jun 24 2019
%o (Sage) (1/(1+2*x^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. A077965.
%K sign
%O 0,3
%A _N. J. A. Sloane_, Nov 17 2002
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