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 A199563 #13 Sep 08 2022 08:46:00
%S A199563 6,46,406,3646,32806,295246,2657206,23914846,215233606,1937102446,
%T A199563 17433922006,156905298046,1412147682406,12709329141646,
%U A199563 114383962274806,1029455660473246,9265100944259206,83385908498332846,750473176484995606
%N A199563 5*9^n+1.
%H A199563 Vincenzo Librandi, <a href="/A199563/b199563.txt">Table of n, a(n) for n = 0..1000</a>
%H A199563 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (10,-9).
%F A199563 a(n) = 2*A135423(n).
%F A199563 a(n) = 9*a(n-1)-8.
%F A199563 a(n) = 10*a(n-1)-9*a(n-2).
%F A199563 G.f.: 2*(3-7*x)/((1-x)*(1-9*x)).
%p A199563 A199563:=n->5*9^n+1; seq(A199563(k), k=0..50); # _Wesley Ivan Hurt_, Oct 24 2013
%t A199563 Table[5*9^n+1, {n,0,50}] (* _Wesley Ivan Hurt_, Oct 24 2013 *)
%o A199563 (Magma) [5*9^n+1: n in [0..30]];
%K A199563 nonn,easy
%O A199563 0,1
%A A199563 _Vincenzo Librandi_, Nov 08 2011