%I #12 May 21 2018 15:12:22

%S 1,3,9,27,79,231,675,1971,5755,16803,49059,143235,418195,1220979,

%T 3564819,10407987,30387571,88720755,259032627,756281907,2208070579,

%U 6446770227,18822245427,54954172467,160446376243,468445588275,1367692273971,3993168476979,11658612678451

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

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (3,0,0,-2).

%t CoefficientList[Series[(1-x)^(-1)/(1-2x-2x^2-2x^3),{x,0,40}],x] (* _Harvey P. Dale_, Mar 27 2011 *)

%o (PARI) Vec((1-x)^(-1)/(1-2*x-2*x^2-2*x^3)+O(x^99)) \\ _Charles R Greathouse IV_, Sep 27 2012

%Y Partial sums of S(n, x), for x=1...11, A021823, A000217, A027941, A061278, A089817, A053142, A092521, A076765, A092420, A097784, A097826.

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_, Nov 17 2002, Jun 05 2007