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 A198855 #22 Sep 08 2022 08:46:00 %S A198855 6,55,447,3583,28671,229375,1835007,14680063,117440511,939524095, %T A198855 7516192767,60129542143,481036337151,3848290697215,30786325577727, %U A198855 246290604621823,1970324836974591,15762598695796735,126100789566373887 %N A198855 a(n) = 7*8^n - 1. %H A198855 Vincenzo Librandi, <a href="/A198855/b198855.txt">Table of n, a(n) for n = 0..1000</a> %H A198855 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (9,-8). %F A198855 a(n) = 8*a(n-1) + 7. %F A198855 a(n) = 9*a(n-1) - 8*a(n-2), n > 1. %F A198855 G.f.: ( 6+x ) / ( (8*x-1)*(x-1) ). - _R. J. Mathar_, Oct 31 2011 %o A198855 (Magma) [7*8^n-1: n in [0..30]] %K A198855 nonn,easy %O A198855 0,1 %A A198855 _Vincenzo Librandi_, Oct 31 2011