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 A016261 #23 Sep 04 2017 03:51:13
%S A016261 1,20,291,3730,44681,513240,5730271,62683550,675263061,7188478660,
%T A016261 75807419051,793377882570,8251512054241,85374719599280,
%U A016261 879483587504631,9026463398652790,92349281698986221,942254646401987100,9591402928728995011,97433737469672066210
%N A016261 Expansion of 1/((1-x)*(1-9*x)*(1-10*x)).
%H A016261 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (20,-109,90).
%F A016261 a(n) = (8*10^(n+2) - 9^(n+3) + 1)/72. - _Bruno Berselli_, Mar 21 2011
%F A016261 a(n) = 19*a(n-1) - 90*a(n-2) + 1, n >= 2. - _Vincenzo Librandi_, Mar 21 2011
%t A016261 Table[(2^(n + 4)*5^(n + 1) - 9^(n + 2) + 1)/72, {n, 40}] (* or *) CoefficientList[Series[1/((1 - z) (1 - 9*z) (1 - 10*z)), {z, 0, 40}], z] (* _Vladimir Joseph Stephan Orlovsky_, Jul 21 2011 *)
%Y A016261 Cf. A016218, A016228.
%K A016261 nonn
%O A016261 0,2
%A A016261 _N. J. A. Sloane_