%I #12 Sep 08 2022 08:46:00
%S 12,100,892,8020,72172,649540,5845852,52612660,473513932,4261625380,
%T 38354628412,345191655700,3106724901292,27960524111620,
%U 251644717004572,2264802453041140,20383222077370252,183448998696332260
%N 11*9^n+1.
%H Vincenzo Librandi, <a href="/A199681/b199681.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (10,-9).
%F a(n) = 9*a(n-1)-8.
%F a(n) = 10*a(n-1)-9*a(n-2).
%F G.f.: 4*(3-5*x)/((1-x)*(1-9*x)).
%t 11*9^Range[0,20]+1 (* or *) LinearRecurrence[{10,-9},{12,100},20] (* _Harvey P. Dale_, Apr 26 2017 *)
%o (Magma) [11*9^n+1: n in [0..30]];
%K nonn,easy
%O 0,1
%A _Vincenzo Librandi_, Nov 09 2011