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 A198688 #16 Sep 08 2022 08:45:59 %S A198688 5,41,293,2057,14405,100841,705893,4941257,34588805,242121641, %T A198688 1694851493,11863960457,83047723205,581334062441,4069338437093, %U A198688 28485369059657,199397583417605,1395783083923241,9770481587462693,68393371112238857 %N A198688 6*7^n-1. %H A198688 Vincenzo Librandi, <a href="/A198688/b198688.txt">Table of n, a(n) for n = 0..1000</a> %H A198688 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (8,-7). %F A198688 a(n) = 7*a(n-1)+6. a(n) = 8*a(n-1)-7*a(n-2), n>1. %F A198688 G.f. ( 5+x ) / ( (7*x-1)*(x-1) ). - R. J. Mathar, Oct 30 2011 %o A198688 (Magma) [6*7^n-1: n in [0..30]] %Y A198688 Cf. A048473, A081655, A198480, A198647. %K A198688 nonn,easy %O A198688 0,1 %A A198688 _Vincenzo Librandi_, Oct 29 2011