The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A198973 8*10^n-1. 1

%I

%S 7,79,799,7999,79999,799999,7999999,79999999,799999999,7999999999,

%T 79999999999,799999999999,7999999999999,79999999999999,

%U 799999999999999,7999999999999999,79999999999999999,799999999999999999,7999999999999999999

%N 8*10^n-1.

%H Vincenzo Librandi, <a href="/A198973/b198973.txt">Table of n, a(n) for n = 0..200</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).

%F a(n) = 10*a(n-1)+9.

%F a(n) = 11*a(n-1)-10*a(n-2), n>1.

%F G.f.: (7 + 2*x)/(1 - 11*x + 10*x^2). - _Vincenzo Librandi_, Jan 04 2013

%t Table[FromDigits[PadRight[{7},n,9]],{n,20}] (* _Harvey P. Dale_, Jun 05 2012 *)

%t CoefficientList[Series[(7 + 2*x)/(1 - 11*x + 10*x^2), {x, 0, 30}], x] (* _Vincenzo Librandi_, Jan 04 2013 *)

%o (MAGMA) [8*10^n-1 : n in [0..20]]

%K nonn,easy

%O 0,1

%A _Vincenzo Librandi_, Nov 02 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 28 03:28 EDT 2022. Contains 354110 sequences. (Running on oeis4.)