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 A074515 #23 Mar 14 2021 12:07:26
%S A074515 3,14,98,794,6818,60074,535538,4799354,43112258,387682634,3487832978,
%T A074515 31385253914,282446313698,2541932937194,22877060890418,
%U A074515 205892205836474,1853024483819138,16677198879535754,150094704016475858
%N A074515 a(n) = 1^n + 4^n + 9^n.
%H A074515 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (14,-49,36).
%F A074515 From _Mohammad K. Azarian_, Dec 26 2008: (Start)
%F A074515 G.f.: 1/(1-x) + 1/(1-4*x) + 1/(1-9*x).
%F A074515 E.g.f.: e^x + e^(4*x) + e^(9*x). (End)
%F A074515 a(n) = 13*a(n-1) - 36*a(n-2) + 24 with a(0)=3, a(1)=14. - _Vincenzo Librandi_, Jul 21 2010
%t A074515 Table[1^n + 4^n + 9^n, {n, 0, 20}]
%t A074515 LinearRecurrence[{14,-49,36},{3,14,98},30] (* _Harvey P. Dale_, Aug 06 2013 *)
%o A074515 (Python)
%o A074515 def a(n): return 1 + 4**n + 9**n
%o A074515 print([a(n) for n in range(19)]) # _Michael S. Branicky_, Mar 14 2021
%Y A074515 Cf. A001550, A001576, A034513, A001579, A074501..A074580.
%Y A074515 Cf. A052539.
%K A074515 easy,nonn
%O A074515 0,1
%A A074515 _Robert G. Wilson v_, Aug 23 2002