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 A074560 #18 Sep 08 2022 08:45:07
%S A074560 3,20,154,1268,10738,92060,794314,6882308,59830498,521657900,
%T A074560 4560585274,39971171348,351149544658,3091623236540,27274843749034,
%U A074560 241075518532388,2134495208609218,18928981642491980,168109034193901594,1494966906911109428,13310586967150560178
%N A074560 a(n) = 3^n + 8^n + 9^n.
%H A074560 Vincenzo Librandi, <a href="/A074560/b074560.txt">Table of n, a(n) for n = 0..1000</a>
%H A074560 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (20,-123,216).
%F A074560 From _Mohammad K. Azarian_, Dec 30 2008: (Start)
%F A074560 G.f.: 1/(1-3*x) + 1/(1-8*x) + 1/(1-9*x).
%F A074560 E.g.f.: exp(3*x) + exp(8*x) + exp(9*x). (End)
%F A074560 a(n) = 20*a(n-1) - 123*a(n-2) + 216*a(n-3) for n>2. - _Wesley Ivan Hurt_, Aug 15 2016
%p A074560 A074560:=n->3^n + 8^n + 9^n: seq(A074560(n), n=0..25); # _Wesley Ivan Hurt_, Aug 15 2016
%t A074560 Table[3^n + 8^n + 9^n, {n, 0, 20}]
%t A074560 LinearRecurrence[{20,-123,216}, {3, 20, 154}, 25] (* _G. C. Greubel_, Aug 15 2016 *)
%o A074560 (Magma) [3^n + 8^n + 9^n: n in [0..20]]; // _Vincenzo Librandi_, Aug 24 2011
%Y A074560 Cf. A001550, A001576, A001579, A034513, A074501-A074580.
%K A074560 easy,nonn
%O A074560 0,1
%A A074560 _Robert G. Wilson v_, Aug 23 2002