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 A198965 #24 Aug 16 2024 11:59:51
%S A198965 6,62,566,5102,45926,413342,3720086,33480782,301327046,2711943422,
%T A198965 24407490806,219667417262,1977006755366,17793060798302,
%U A198965 160137547184726,1441237924662542,12971141321962886,116740271897665982,1050662447078993846,9455962023710944622,85103658213398501606
%N A198965 a(n) = 7*9^n - 1.
%H A198965 Vincenzo Librandi, <a href="/A198965/b198965.txt">Table of n, a(n) for n = 0..1000</a>
%H A198965 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>,signature (10,-9).
%F A198965 a(n) = 9*a(n-1)+8.
%F A198965 a(n) = 10*a(n-1)-9*a(n-2), n>1.
%F A198965 G.f.: 2*(3 + x)/(1 - 10*x + 9*x^2). - _Vincenzo Librandi_, Jan 03 2013
%F A198965 From _Elmo R. Oliveira_, Aug 16 2024: (Start)
%F A198965 E.g.f.: exp(x)*(7*exp(8*x) - 1).
%F A198965 a(n) = 2*A198964(n). (End)
%t A198965 CoefficientList[Series[2 (3 + x)/(1 - 10 x + 9 x^2), {x, 0, 30}], x] (* _Vincenzo Librandi_, Jan 03 2013 *)
%t A198965 NestList[9#+8&,6,20] (* or *) LinearRecurrence[{10,-9},{6,62},20] (* _Harvey P. Dale_, Feb 26 2015 *)
%o A198965 (Magma) [7*9^n-1: n in [0..20]];
%o A198965 (PARI) a(n)=7*9^n-1 \\ _Charles R Greathouse IV_, Jul 05 2024
%Y A198965 Cf. A198964.
%K A198965 nonn,easy
%O A198965 0,1
%A A198965 _Vincenzo Librandi_, Nov 01 2011