%I #16 Jun 13 2015 00:50:01
%S 0,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,
%T -2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,
%U 3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3,-2,3
%N Expansion of x*(3-2*x)/(1-x^2).
%H B. R. Myers, <a href="http://dx.doi.org/10.1137/1017045">On Spanning Trees, Weighted Compositions, Fibonacci Numbers, and Resistor Networks</a>, SIAM Rev., 17 (1975), 465-474.
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (0,1).
%F a(n) = (1-5*(-1)^n)/2 for n>0. - _Colin Barker_, Jun 09 2015
%F a(n) = a(n-2) for n>2. - _Colin Barker_, Jun 09 2015
%t CoefficientList[Series[x (3-2x)/(1-x^2),{x,0,150}],x] (* _Harvey P. Dale_, Mar 23 2011 *)
%o (PARI) Vec(x*(3-2*x)/(1-x^2)+O(x^99)) \\ _Charles R Greathouse IV_, Sep 27 2012
%K sign,easy
%O 0,2
%A _N. J. A. Sloane_