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 A133680 #10 Jan 02 2024 08:56:34
%S A133680 1,8,128,1600,22016,291328,3915776,52301824,700350464,9368535040,
%T A133680 125373513728,1677522632704,22447074050048,300358221955072,
%U A133680 4019055107244032,53778232838717440,719597830431309824
%N A133680 a(n)=8*a(n-1)+72*a(n-2) for n>=3, a(0)=1, a(1)=8, a(2)=128 .
%H A133680 Harvey P. Dale, <a href="/A133680/b133680.txt">Table of n, a(n) for n = 0..887</a>
%H A133680 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (8,72).
%F A133680 G.f.: (1-8*x^2)/(1-8*x-72*x^2) . a(n) = Sum_{k, 0<=k<=n}A122950(n,k)*8^k .
%t A133680 LinearRecurrence[{8,72},{1,8,128},20] (* _Harvey P. Dale_, Sep 15 2015 *)
%K A133680 easy,nonn
%O A133680 0,2
%A A133680 _Philippe Deléham_, Dec 31 2007