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%I #14 Mar 13 2024 19:54:36
%S 2,20,218,2396,26354,289892,3188810,35076908,385845986,4244305844,
%T 46687364282,513561007100,5649171078098,62140881859076,
%U 683549700449834,7519046704948172,82709513754429890,909804651298728788,10007851164286016666
%N (9*11^n+1)/5.
%H Vincenzo Librandi, <a href="/A199761/b199761.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 a(n) = 11*a(n-1)-2.
%F a(n) = 12*a(n-1)-11*a(n-2).
%F G.f.: 2*(1-2*x)/((1-x)*(1-11*x)).
%t (9*11^Range[0,20]+1)/5 (* or *) LinearRecurrence[{12,-11},{2,20},20] (* _Harvey P. Dale_, Mar 13 2024 *)
%o (Magma) [(9*11^n+1)/5: n in [0..30]];
%K nonn,easy
%O 0,1
%A _Vincenzo Librandi_, Nov 10 2011