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 A074553 #18 Sep 08 2022 08:45:07
%S A074553 3,16,98,664,4802,36136,278498,2177464,17174402,136190536,1083566498,
%T A074553 8638939864,68964148802,550978111336,4404154809698,35214904015864,
%U A074553 281627607648002,2252562882278536,18018213594168098,144134262724445464
%N A074553 a(n) = 3^n + 5^n + 8^n.
%H A074553 Vincenzo Librandi, <a href="/A074553/b074553.txt">Table of n, a(n) for n = 0..200</a>
%H A074553 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (16,-79,120).
%F A074553 From _Mohammad K. Azarian_, Dec 30 2008: (Start)
%F A074553 G.f.: 1/(1-3*x) + 1/(1-5*x) + 1/(1-8*x).
%F A074553 E.g.f.: exp(3*x) + exp(5*x) + exp(8*x). (End)
%F A074553 a(n) = 16*a(n-1) - 79*a(n-2) + 120*a(n-3).
%t A074553 Table[3^n + 5^n + 8^n, {n, 0, 20}]
%o A074553 (Magma) [3^n + 5^n + 8^n: n in [0..30]]; // _Vincenzo Librandi_, Jun 13 2011
%Y A074553 Cf. A001550, A001576, A034513, A001579, A074501 - A074580.
%K A074553 easy,nonn
%O A074553 0,1
%A A074553 _Robert G. Wilson v_, Aug 23 2002