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 A199555 #10 Sep 08 2022 08:46:00 %S A199555 8,57,449,3585,28673,229377,1835009,14680065,117440513,939524097, %T A199555 7516192769,60129542145,481036337153,3848290697217,30786325577729, %U A199555 246290604621825,1970324836974593,15762598695796737,126100789566373889 %N A199555 7*8^n+1. %H A199555 Vincenzo Librandi, <a href="/A199555/b199555.txt">Table of n, a(n) for n = 0..1000</a> %H A199555 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (9,-8). %F A199555 a(n) = 8*a(n-1)-7. %F A199555 a(n) = 9*a(n-1)-8*a(n-2). %F A199555 G.f.: (8-15*x)/((1-x)*(1-8*x)). %o A199555 (Magma) [7*8^n+1: n in [0..30]]; %K A199555 nonn,easy %O A199555 0,1 %A A199555 _Vincenzo Librandi_, Nov 08 2011