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A198699 7*10^n-1 1
6, 69, 699, 6999, 69999, 699999, 6999999, 69999999, 699999999, 6999999999, 69999999999, 699999999999, 6999999999999, 69999999999999, 699999999999999, 6999999999999999, 69999999999999999, 699999999999999999 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

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

FORMULA

a(n) = 10*a(n-1)+9. a(n) = 11*a(n-1)-10*a(n-2), n>1.

G.f. ( 6+3*x ) / ( (10*x-1)*(x-1) ). - R. J. Mathar, Oct 29 2011

MATHEMATICA

NestList[10#+9&, 6, 20] (* or *) LinearRecurrence[{11, -10}, {6, 69}, 20] (* Harvey P. Dale, Dec 29 2013 *)

PROG

(MAGMA) [7*10^n-1: n in [0..30]]

CROSSREFS

Cf. A002283, A109002.

Sequence in context: A296016 A288719 A201535 * A258792 A214694 A234509

Adjacent sequences:  A198696 A198697 A198698 * A198700 A198701 A198702

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Oct 29 2011

STATUS

approved

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Last modified April 3 23:48 EDT 2020. Contains 333207 sequences. (Running on oeis4.)