A013720 - OEIS

%I #25 Sep 08 2022 08:44:38

%S 15,3375,759375,170859375,38443359375,8649755859375,1946195068359375,

%T 437893890380859375,98526125335693359375,22168378200531005859375,

%U 4987885095119476318359375,1122274146401882171630859375

%N a(n) = 15^(2*n + 1).

%H Vincenzo Librandi, <a href="/A013720/b013720.txt">Table of n, a(n) for n = 0..200</a>

%H Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>

%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (225).

%F From _Philippe Deléham_, Nov 25 2008: (Start)

%F a(n) = 225*a(n-1), a(0)=15.

%F G.f.: 15/(1-225*x). (End)

%p seq(15^(2*n+1),n=0..11); # _Nathaniel Johnston_, Jun 25 2011

%t 15^(2Range[0,12]+1)  (* _Harvey P. Dale_, Feb 09 2011 *)

%o (Magma) [15^(2*n+1): n in [0..15]]; // _Vincenzo Librandi_, Jun 26 2011

%o (PARI) a(n)=15^(2*n+1) \\ _Charles R Greathouse IV_, Jul 11 2016

%Y Bisection of A001024 (15^n).

%K nonn,easy

%O 0,1

%A _N. J. A. Sloane_