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 A013733 #35 Sep 08 2022 08:44:38
%S A013733 9,243,6561,177147,4782969,129140163,3486784401,94143178827,
%T A013733 2541865828329,68630377364883,1853020188851841,50031545098999707,
%U A013733 1350851717672992089,36472996377170786403,984770902183611232881,26588814358957503287787
%N A013733 a(n) = 3^(3n+2).
%C A013733 Additive digital root of a(n) is equal to 9. - _Miquel Cerda_, Oct 31 2016
%H A013733 Vincenzo Librandi, <a href="/A013733/b013733.txt">Table of n, a(n) for n = 0..200</a>
%H A013733 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>
%H A013733 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (27).
%F A013733 a(n)=27*a(n-1), n>0 ; a(0)=9 . G.f.: 9/(1-27*x). - _Philippe Deléham_, Nov 25 2008
%p A013733 seq(3^(3*n+2),n=0..15); # _Nathaniel Johnston_, Jun 26 2011
%t A013733 Table[3^(3n+2), {n,0,100}] (* _Wesley Ivan Hurt_, Oct 24 2013 *)
%o A013733 (Magma) [3^(3*n+2): n in [0..25]]; // _Vincenzo Librandi_, May 25 2011
%o A013733 (PARI) a(n)=3^(3*n+2) \\ _Charles R Greathouse IV_, Jul 11 2016
%Y A013733 Cf. A013731, A013732, A013735, A013737.
%K A013733 nonn,easy
%O A013733 0,1
%A A013733 _N. J. A. Sloane_