%I #16 Apr 07 2020 03:37:08

%S 1,-2,0,6,-10,-2,34,-50,-22,190,-246,-178,1050,-1186,-1270,5742,-5574,

%T -8450,31082,-25330,-53734,166558,-109750,-330834,883450,-441282,

%U -1987286,4636750,-1544742,-11703330,24066314,-3749138,-67790150,123421054,4660970,-387083378,624603546

%N Expansion of (1-x)/(1+x+2*x^2-2*x^3).

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (-1,-2,2).

%F a(0) = 1, a(1) = -2, a(2) = 0, a(n) = -a(n-1) - 2*a(n-2) + 2*a(n-3) for n > 2. - _Harvey P. Dale_, Dec 11 2011

%t CoefficientList[Series[(1-x)/(1+x+2x^2-2x^3),{x,0,40}],x] (* or *) LinearRecurrence[{-1,-2,2},{1,-2,0},40] (* _Harvey P. Dale_, Dec 11 2011 *)

%o (PARI) Vec((1-x)/(1+x+2*x^2-2*x^3) + O(x^50)) \\ _Jinyuan Wang_, Apr 07 2020

%Y First differences of A077977.

%K sign,easy

%O 0,2

%A _N. J. A. Sloane_, Nov 17 2002