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 A074550 #16 Sep 08 2022 08:45:07
%S A074550 3,15,89,603,4433,34035,266969,2115723,16849313,134499555,1074849449,
%T A074550 8594306043,68736785393,549824517075,4398319729529,35185460179563,
%U A074550 281479314724673,2251817122694595,18014467616379209,144115464116024283
%N A074550 a(n) = 3^n + 4^n + 8^n.
%H A074550 Vincenzo Librandi, <a href="/A074550/b074550.txt">Table of n, a(n) for n = 0..200</a>
%H A074550 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (15,-68,96).
%F A074550 From _Mohammad K. Azarian_, Dec 28 2008: (Start)
%F A074550 G.f.: 1/(1-3*x) + 1/(1-4*x) + 1/(1-8*x).
%F A074550 E.g.f.: exp(3*x) + exp(4*x) + exp(8*x). (End)
%F A074550 a(n) = 15*a(n-1) - 68*a(n-2) + 96*a(n-3).
%t A074550 Table[3^n + 4^n + 8^n, {n, 0, 20}]
%o A074550 (Magma) [3^n + 4^n + 8^n: n in [0..30]]; // _Vincenzo Librandi_, Jun 13 2011
%Y A074550 Cf. A001550, A001576, A034513, A001579, A074501 - A074580.
%K A074550 easy,nonn
%O A074550 0,1
%A A074550 _Robert G. Wilson v_, Aug 23 2002