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(9*11^n+1)/10.
2

%I #13 Sep 08 2022 08:46:00

%S 1,10,109,1198,13177,144946,1594405,17538454,192922993,2122152922,

%T 23343682141,256780503550,2824585539049,31070440929538,

%U 341774850224917,3759523352474086,41354756877214945,454902325649364394,5003925582143008333

%N (9*11^n+1)/10.

%H Vincenzo Librandi, <a href="/A199760/b199760.txt">Table of n, a(n) for n = 0..900</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (12,-11).

%F G.f.: (1-2*x)/((1-x)*(1-11*x)).

%F a(n) = 12*a(n-1)-11*a(n-2).

%F a(n) = 11*a(n-1)-1.

%F a(n) = 11^n - sum(11^i, i=0..n-1) for n>0. [_Bruno Berselli_, Jun 20 2013]

%o (Magma) [(9*11^n+1)/10: n in [0..30]];

%K nonn,easy

%O 0,2

%A _Vincenzo Librandi_, Nov 10 2011