%I #19 Sep 08 2022 08:45:51

%S 24,744,7944,79944,799944,7999944,79999944,799999944,7999999944,

%T 79999999944,799999999944,7999999999944,79999999999944,

%U 799999999999944,7999999999999944,79999999999999944,799999999999999944

%N a(n) = 8*(10^n-7).

%H Vincenzo Librandi, <a href="/A175604/b175604.txt">Table of n, a(n) for n = 1..100</a>

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

%F G.f.: 8*x*(3 + 60*x)/((1 - x)*(1 - 10*x)). - _Vincenzo Librandi_, Aug 24 2014

%F a(n) = 11*a(n-1) - 10*a(n-2). - _Vincenzo Librandi_, Aug 24 2014

%F a(n) = 10*a(n-1) + 504. - _Robert Israel_, Aug 24 2014

%t Table[8 (10^n - 7), {n, 20}] (* or *) CoefficientList[Series[8 (3 + 60 x)/((1 - x) (1 - 10 x)), {x, 0, 20}], x] (* _Vincenzo Librandi_, Aug 24 2014 *)

%o (Magma) [8*(10^n-7): n in [1..20]]; // _Vincenzo Librandi_, Aug 24 2014

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Jun 15 2010