%I #15 Mar 20 2020 12:50:59

%S 9,279,2979,29979,299979,2999979,29999979,299999979,2999999979,

%T 29999999979,299999999979,2999999999979,29999999999979,

%U 299999999999979,2999999999999979,29999999999999979,299999999999999979

%N 3*(10^n-7).

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).

%F G.f 9*x*(1+20*x) / ( (10*x-1)*(x-1) ). a(n) = 9*A033175(n-1). - R. J. Mathar, Jan 06 2011

%t 3(10^Range[20]-7) (* or *) LinearRecurrence[{11,-10},{9,279},20] (* _Harvey P. Dale_, Mar 20 2020 *)

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Nov 15 2010