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 A013887 #17 Sep 08 2022 08:44:38 %S A013887 324,612220032,1156831381426176,2185911559738696531968, %T A013887 4130428534112329328517709824,7804725584345565904628551916716032, %U A013887 14747559712960682275277163588165279154176,27866516911699690485530919446962290200798035968 %N A013887 a(n) = 18^(5*n + 2). %H A013887 Vincenzo Librandi, <a href="/A013887/b013887.txt">Table of n, a(n) for n = 0..50</a> %H A013887 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a> %H A013887 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1889568). %F A013887 a(n) = 1889568*a(n-1), a(0)=324. - _Vincenzo Librandi_, May 27 2011 %o A013887 (Magma) [18^(5*n+2): n in [0..10]]; // _Vincenzo Librandi_, May 27 2011 %Y A013887 Cf. A001027. %K A013887 nonn %O A013887 0,1 %A A013887 _N. J. A. Sloane_