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 A074529 #18 Sep 08 2022 08:45:07
%S A074529 3,12,62,378,2498,17082,118442,825858,5771618,40373802,282535322,
%T A074529 1977505938,13841822738,96890612922,678227872202,4747575891618,
%U A074529 33232973681858,232630643258442,1628413985593082,11398896348158898
%N A074529 a(n) = 2^n + 3^n + 7^n.
%H A074529 Vincenzo Librandi, <a href="/A074529/b074529.txt">Table of n, a(n) for n = 0..200</a>
%H A074529 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (12,-41,42).
%F A074529 From _Mohammad K. Azarian_, Dec 27 2008: (Start)
%F A074529 G.f.: 1/(1-2*x) + 1/(1-3*x) + 1/(1-7*x).
%F A074529 E.g.f.: exp(2*x) + exp(3*x) + exp(7*x). (End)
%t A074529 Table[2^n + 3^n + 7^n, {n, 0, 20}]
%t A074529 LinearRecurrence[{12,-41,42},{3,12,62},20] (* _Harvey P. Dale_, Mar 29 2020 *)
%o A074529 (Magma) [2^n + 3^n + 7^n: n in [0..25]]; // _Vincenzo Librandi_, Jun 11 2011
%Y A074529 Cf. A001550, A001576, A034513, A001579, A074501 - A074580.
%K A074529 easy,nonn
%O A074529 0,1
%A A074529 _Robert G. Wilson v_, Aug 23 2002