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 A074539 #23 Sep 08 2022 08:45:07
%S A074539 3,15,93,645,4737,35925,277833,2175405,17168097,136171365,1083508473,
%T A074539 8638764765,68963621457,550976525205,4404150043113,35214889699725,
%U A074539 281627564666817,2252562753269445,18018213207009753,144134261562708285
%N A074539 a(n) = 2^n + 5^n + 8^n.
%H A074539 Vincenzo Librandi, <a href="/A074539/b074539.txt">Table of n, a(n) for n = 0..200</a>
%H A074539 D. Suprijanto, I. W. Suwarno, <a href="http://dx.doi.org/10.12988/ams.2014.4139">Observation on Sums of Powers of Integers Divisible by 3k-1</a>, Applied Mathematical Sciences, Vol. 8, 2014, no. 45, pp. 2211-2217.
%H A074539 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (15,-66,80).
%F A074539 From _Mohammad K. Azarian_, Dec 27 2008: (Start)
%F A074539 G.f.: 1/(1-2*x) + 1/(1-5*x) + 1/(1-8*x).
%F A074539 E.g.f.: exp(2*x) + exp(5*x) + exp(8*x). (End)
%t A074539 Table[2^n + 5^n + 8^n, {n, 0, 20}]
%o A074539 (Magma) [2^n + 5^n + 8^n: n in [0..25]]; // _Vincenzo Librandi_, Jun 11 2011
%Y A074539 Cf. A001550, A001576, A034513, A001579, A074501 - A074580.
%K A074539 easy,nonn
%O A074539 0,1
%A A074539 _Robert G. Wilson v_, Aug 23 2002