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 A009991 #44 Jul 12 2023 12:49:04 %S A009991 1,47,2209,103823,4879681,229345007,10779215329,506623120463, %T A009991 23811286661761,1119130473102767,52599132235830049, %U A009991 2472159215084012303,116191483108948578241,5460999706120583177327 %N A009991 Powers of 47. %C A009991 Same as Pisot sequences E(1, 47), L(1, 47), P(1, 47), T(1, 47). Essentially same as Pisot sequences E(47, 2209), L(47, 2209), P(47, 2209), T(47, 2209). See A008776 for definitions of Pisot sequences. %C A009991 The compositions of n in which each natural number is colored by one of p different colors are called p-colored compositions of n. For n >= 1, a(n) equals the number of 47-colored compositions of n such that no adjacent parts have the same color. - _Milan Janjic_, Nov 17 2011 %C A009991 Numbers n such that sigma(47*n) = 47*n + sigma(n). - _Jahangeer Kholdi_, Nov 24 2013 %H A009991 T. D. Noe, <a href="/A009991/b009991.txt">Table of n, a(n) for n = 0..100</a> %H A009991 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a> %H A009991 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (47). %F A009991 G.f.: 1/(1-47*x). - _Philippe Deléham_, Nov 24 2008 %F A009991 a(n) = 47^n; a(n) = 47*a(n-1), a(0)=1. - _Vincenzo Librandi_, Nov 21 2010 %t A009991 47^Range[0, 13] (* _Michael De Vlieger_, Jan 13 2018 *) %o A009991 (Magma)[47^n: n in [0..20]] // _Vincenzo Librandi_, Nov 21 2010 %o A009991 (PARI) a(n)=47^n \\ _Charles R Greathouse IV_, Oct 07 2015 %K A009991 nonn,easy %O A009991 0,2 %A A009991 _N. J. A. Sloane_