This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A199760 #20 Mar 28 2025 12:08:51
%S A199760 1,10,109,1198,13177,144946,1594405,17538454,192922993,2122152922,
%T A199760 23343682141,256780503550,2824585539049,31070440929538,
%U A199760 341774850224917,3759523352474086,41354756877214945,454902325649364394,5003925582143008333,55043181403573091662,605474995439304008281
%N A199760 a(n) = (9*11^n + 1)/10.
%H A199760 Vincenzo Librandi, <a href="/A199760/b199760.txt">Table of n, a(n) for n = 0..900</a>
%H A199760 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (12,-11).
%F A199760 G.f.: (1-2*x)/((1-x)*(1-11*x)).
%F A199760 a(n) = 12*a(n-1) - 11*a(n-2).
%F A199760 a(n) = 11*a(n-1) - 1.
%F A199760 a(n) = 11^n - Sum_{i=0..n-1} 11^i for n > 0. - _Bruno Berselli_, Jun 20 2013
%F A199760 From _Elmo R. Oliveira_, Mar 25 2025: (Start)
%F A199760 E.g.f.: exp(x)*(9*exp(10*x) + 1)/10.
%F A199760 a(n) = A199763(n)/10. (End)
%t A199760 (9*11^Range[0, 20] + 1)/10 (* _Paolo Xausa_, Mar 28 2025 *)
%o A199760 (Magma) [(9*11^n+1)/10: n in [0..30]];
%Y A199760 Cf. A199763.
%K A199760 nonn,easy
%O A199760 0,2
%A A199760 _Vincenzo Librandi_, Nov 10 2011