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

%I #12 Aug 07 2015 02:41:05

%S 1,3,7,17,41,97,229,541,1277,3013,7109,16773,39573,93365,220277,

%T 519701,1226133,2892821,6825045,16102357,37990357,89630805,211466325,

%U 498913365,1177088341,2777109333,6552045397,15458267477,36470753621,86045598037,203007731029

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

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

%p A052912 := proc(n) if n < 0 then 0; else coeftayl( 1/(1-2*x^3-2*x),x=0,n) ; end if; end proc:

%p A077851 := proc(n) 2*(2*A052912(n)+A052912(n-1)+A052912(n-2))-1 ; %/3 ; end proc:

%p seq(A077851(n),n=0..15) ; # _R. J. Mathar_, Mar 28 2011

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

%K nonn,easy

%O 0,2

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