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 A155198 #15 Jan 03 2024 08:47:51
%S A155198 1,8,72,656,5976,54440,495936,4517864,41156712,374928272,3415511160,
%T A155198 31114528712,283446269568,2582130954824,23522624862984,
%U A155198 214285754721680,1952094417358104,17783135510944616,162000314015859648
%N A155198 a(n)=9*a(n-1)+a(n-2), n>2 ; a(0)=1, a(1)=8, a(2)=72 .
%H A155198 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (9,1).
%F A155198 G.f.: (1-x-x^2)/(1-9*x-x^2).
%F A155198 a(n) = Sum_{k, 0<=k<=n} A155161(n,k)*8^k. - _Philippe Deléham_, Feb 08 2012
%t A155198 LinearRecurrence[{9,1},{1,8,72},20] (* _Harvey P. Dale_, Aug 22 2016 *)
%K A155198 nonn,easy
%O A155198 0,2
%A A155198 _Philippe Deléham_, Jan 21 2009