A179555 a(1)=10; a(n) = a(n-1)*10 - 1.

10, 99, 989, 9889, 98889, 988889, 9888889, 98888889, 988888889, 9888888889, 98888888889, 988888888889, 9888888888889, 98888888888889, 988888888888889, 9888888888888889, 98888888888888889, 988888888888888889, 9888888888888888889, 98888888888888888889

Offset

1,1

Comments

For n -> oo, a(n)/10^n -> 0.9888......8889 = 89/90.

Links

Colin Barker, Table of n, a(n) for n = 1..999

Index entries for linear recurrences with constant coefficients, signature (11,-10).

Formula

From Colin Barker, Oct 03 2015: (Start)

a(n) = 11*a(n-1) - 10*a(n-2) for n>2.

G.f.: -x*(11*x-10) / ((x-1)*(10*x-1)).

(End)

Mathematica

a[1] := 10; a[n_] := a[n] = 10 a[n - 1] - 1; Array[a@ # &, {20}] (* Michael De Vlieger, Oct 03 2015 *)

Prog

(PARI) Vec(-x*(11*x-10)/((x-1)*(10*x-1)) + O(x^30)) \\ Colin Barker, Oct 03 2015

Crossrefs

Sequence in context: A179558 A179556 A179477 * A105694 A179557 A300000

Adjacent sequences: A179552 A179553 A179554 * A179556 A179557 A179558

Keyword

nonn,easy

Author

Mark Dols, Jul 19 2010

Extensions

Name edited by Colin Barker, Oct 03 2015

Status

approved