A198698 a(n) = 3*10^n-1.

2, 29, 299, 2999, 29999, 299999, 2999999, 29999999, 299999999, 2999999999, 29999999999, 299999999999, 2999999999999, 29999999999999, 299999999999999, 2999999999999999, 29999999999999999, 299999999999999999

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

G.f.: ( 2+7*x ) / ( (10*x-1)*(x-1) ). - R. J. Mathar, Oct 30 2011

Prog

(Magma) [3*10^n-1: n in [0..30]]

Crossrefs

Cf. A002283, A109002.

Sequence in context: A160952 A088615 A091716 * A094940 A152274 A183722

Adjacent sequences: A198695 A198696 A198697 * A198699 A198700 A198701

Keyword

nonn,easy

Author

Vincenzo Librandi, Oct 29 2011

Status

approved