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 A198764 #15 Sep 08 2022 08:46:00
%S A198764 5,29,149,749,3749,18749,93749,468749,2343749,11718749,58593749,
%T A198764 292968749,1464843749,7324218749,36621093749,183105468749,
%U A198764 915527343749,4577636718749,22888183593749,114440917968749,572204589843749,2861022949218749
%N A198764 6*5^n-1.
%H A198764 Vincenzo Librandi, <a href="/A198764/b198764.txt">Table of n, a(n) for n = 0..1000</a>
%H A198764 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (6,-5).
%F A198764 a(n) = 5*a(n-1)+4.
%F A198764 a(n) = 6*a(n-1)-5*a(n-2), n>1.
%F A198764 G.f.: (5 - x)/(1 - 6*x + 5*x^2). - _Vincenzo Librandi_, Jan 04 2013
%t A198764 CoefficientList[Series[(5 - x)/(1 - 6*x + 5*x^2), {x, 0, 30}], x] (* _Vincenzo Librandi_, Jan 04 2013 *)
%t A198764 6*5^Range[0,30]-1 (* or *) LinearRecurrence[{6,-5},{5,29},30] (* _Harvey P. Dale_, Dec 21 2014 *)
%o A198764 (Magma) [6*5^n-1: n in [0..30]]
%Y A198764 Cf. A024049, A057651, A081655.
%K A198764 nonn,easy
%O A198764 0,1
%A A198764 _Vincenzo Librandi_, Oct 30 2011