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 A005052 #30 Aug 14 2024 19:39:17 %S A005052 10,30,90,270,810,2430,7290,21870,65610,196830,590490,1771470,5314410, %T A005052 15943230,47829690,143489070,430467210,1291401630,3874204890, %U A005052 11622614670,34867844010,104603532030,313810596090,941431788270,2824295364810,8472886094430 %N A005052 a(n) = 10*3^n. %H A005052 Vincenzo Librandi, <a href="/A005052/b005052.txt">Table of n, a(n) for n = 0..300</a> %H A005052 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a> %H A005052 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (3). %F A005052 From _Elmo R. Oliveira_, Aug 14 2024: (Start) %F A005052 G.f.: 10/(1-3*x). %F A005052 E.g.f.: 10*exp(3*x). %F A005052 a(n) = 3*a(n-1), n > 0. (End) %t A005052 10*3^Range[0, 60] (* _Vladimir Joseph Stephan Orlovsky_, Jun 09 2011 *) %o A005052 (Magma) [10*3^n: n in [0..30]]; // _Vincenzo Librandi_, Jun 10 2011 %o A005052 (PARI) a(n)=10*3^n \\ _Charles R Greathouse IV_, Oct 07 2015 %Y A005052 Except for initial terms, same as A062107. %K A005052 nonn,easy %O A005052 0,1 %A A005052 _N. J. A. Sloane_