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 A173811 #25 Sep 09 2024 20:38:36
%S A173811 3,83,883,8883,88883,888883,8888883,88888883,888888883,8888888883,
%T A173811 88888888883,888888888883,8888888888883,88888888888883,
%U A173811 888888888888883,8888888888888883,88888888888888883,888888888888888883,8888888888888888883,88888888888888888883,888888888888888888883
%N A173811 a(n) = (8*10^n - 53)/9 for n > 0.
%H A173811 Vincenzo Librandi, <a href="/A173811/b173811.txt">Table of n, a(n) for n = 1..100</a>
%H A173811 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).
%F A173811 a(n) = 10*a(n-1) + 53 for n > 0, a(0) = -5.
%F A173811 From _Vincenzo Librandi_, Jul 05 2012: (Start)
%F A173811 G.f.: x*(3+50*x)/((1-x)*(1-10*x)).
%F A173811 a(n) = 11*a(n-1) - 10*a(n-2). (End)
%F A173811 E.g.f.: exp(x)*(8*exp(9*x) - 53)/9. - _Elmo R. Oliveira_, Sep 09 2024
%t A173811 NestList[10#+53&,3,20] (* _Harvey P. Dale_, Jun 13 2011 *)
%t A173811 CoefficientList[Series[(3+50*x)/((1-x)*(1-10*x)),{x,0,30}],x] (* _Vincenzo Librandi_, Jul 05 2012 *)
%o A173811 (Magma)[(8*10^n-53)/9: n in [1..20]]; // _Vincenzo Librandi_, Jul 05 2012
%Y A173811 Cf. A093166.
%K A173811 nonn,easy
%O A173811 1,1
%A A173811 _Vincenzo Librandi_, Feb 25 2010