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 A133671 #15 Jan 02 2024 08:56:24
%S A133671 1,8,-56,-568,3016,39368,-153656,-2673208,7160776,178246088,
%T A133671 -280043576,-11687793208,6234995656,754253760968,355214038984,
%U A133671 -47917026662968,-70650725157944,2996038981272008,7517685391380424,-184228809410028088
%N A133671 a(n) = a(n-1) - 64*a(n-2), a(0)=1, a(1)=8.
%H A133671 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (1, -64).
%F A133671 G.f.: (1+7*x)/(1-x+64*x^2).
%F A133671 a(n) = Sum_{k=0..n} A133607(n,k)*8^k. - _Philippe Deléham_, Dec 30 2007
%Y A133671 Cf. A133607.
%K A133671 easy,sign
%O A133671 0,2
%A A133671 _Philippe Deléham_, Dec 29 2007