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 A198689 #16 Sep 08 2022 08:45:59 %S A198689 7,55,391,2743,19207,134455,941191,6588343,46118407,322828855, %T A198689 2259801991,15818613943,110730297607,775112083255,5425784582791, %U A198689 37980492079543,265863444556807,1861044111897655,13027308783283591,91191161482985143 %N A198689 8*7^n-1. %H A198689 Vincenzo Librandi, <a href="/A198689/b198689.txt">Table of n, a(n) for n = 0..1000</a> %H A198689 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (8,-7). %F A198689 a(n) = 7*a(n-1)+6. a(n) = 8*a(n-1)-7*a(n-2), n>1. %F A198689 G.f. ( 7-x ) / ( (7*x-1)*(x-1) ). - R. J. Mathar, Oct 30 2011 %o A198689 (Magma) [8*7^n-1: n in [0..30]] %Y A198689 Cf. A024075, A048473, A081655, A198480, A198647. %K A198689 nonn,easy %O A198689 0,1 %A A198689 _Vincenzo Librandi_, Oct 29 2011