%I
%S 1,0,1,2,1,4,3,6,11,0,23,22,23,68,21,114,157,72,385,242,529,
%T 1012,45,2070,1979,2160,6119,1798,10439,14036,6843,34914,21229,
%U 48600,91057,6142,188257,175972,200541,552486,151403,953568,1256375,650762,3163511,1861988,4465035
%N Expansion of 1/(1+x^2+2*x^3).
%H G. C. Greubel, <a href="/A077963/b077963.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 (0,1,2).
%F a(n) = (1)^n * A077912(n).  _G. C. Greubel_, Jun 23 2019
%t CoefficientList[Series[1/(1+x^2+2*x^3), {x,0,50}], x] (* or *) LinearRecurrence[{0,1,2}, {1,0,1}, 50] (* _G. C. Greubel_, Jun 23 2019 *)
%o (PARI) my(x='x+O('x^50)); Vec(1/(1+x^2+2*x^3)) \\ _G. C. Greubel_, Jun 23 2019
%o (MAGMA) R<x>:=PowerSeriesRing(Integers(), 50); Coefficients(R!( 1/(1+x^2+2*x^3) )); // _G. C. Greubel_, Jun 23 2019
%o (Sage) (1/(1+x^2+2*x^3)).series(x, 50).coefficients(x, sparse=False) # _G. C. Greubel_, Jun 23 2019
%o (GAP) a:=[1,0,1];; for n in [4..50] do a[n]:=a[n2]2*a[n3]; od; a; # _G. C. Greubel_, Jun 23 2019
%Y Cf. A077912.
%K sign,easy
%O 0,4
%A _N. J. A. Sloane_, Nov 17 2002
