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 A074624 #29 Mar 13 2023 03:14:52
%S A074624 2,17,145,1241,10657,91817,793585,6880121,59823937,521638217,
%T A074624 4560526225,39970994201,351149013217,3091621642217,27274838966065,
%U A074624 241075504183481,2134495165562497,18928981513351817,168109033806481105
%N A074624 a(n) = 8^n + 9^n.
%H A074624 G. C. Greubel, <a href="/A074624/b074624.txt">Table of n, a(n) for n = 0..1000</a>
%H A074624 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (17,-72).
%F A074624 From _Mohammad K. Azarian_, Jan 11 2009: (Start)
%F A074624 G.f.: 1/(1-8*x) + 1/(1-9*x).
%F A074624 E.g.f.: exp(8*x) + exp(9*x). (End)
%F A074624 a(n) = 17*a(n-1) - 72*a(n-2) with a(0)=2, a(1)=17. - _Vincenzo Librandi_, Jul 21 2010
%p A074624 seq(8^n+9^n,n=0..30); # _Robert Israel_, Mar 11 2023
%t A074624 Table[8^n + 9^n, {n, 0, 20}]
%o A074624 (PARI) a(n)=8^n+9^n \\ _Charles R Greathouse IV_, Apr 08 2016
%o A074624 (Magma) [8^n+9^n: n in [0..30]]; // _G. C. Greubel_, Mar 11 2023
%o A074624 (SageMath) [8^n+9^n for n in range(31)] # _G. C. Greubel_, Mar 11 2023
%Y A074624 Cf. A007689, A034472, A063376, A063481, A074600..A074623.
%K A074624 easy,nonn
%O A074624 0,1
%A A074624 _Robert G. Wilson v_, Aug 26 2002