A198967 10*9^n-1.

9, 89, 809, 7289, 65609, 590489, 5314409, 47829689, 430467209, 3874204889, 34867844009, 313810596089, 2824295364809, 25418658283289, 228767924549609, 2058911320946489, 18530201888518409, 166771816996665689, 1500946352969991209

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients,signature (10,-9).

Formula

a(n) = 9*a(n-1)+8. a(n) = 10*a(n-1)-9*a(n-2), n>1.

G.f.: (9 - x)/(1 - 10*x + 9*x^2). - Vincenzo Librandi, Jan 03 2013

Mathematica

CoefficientList[Series[(9 - x)/(1 - 10*x + 9*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 03 2013 *)

Prog

(Magma) [10*9^n-1: n in [0..20]]

Crossrefs

Sequence in context: A064616 A133486 A224760 * A320093 A015584 A072256

Adjacent sequences: A198964 A198965 A198966 * A198968 A198969 A198970

Keyword

nonn,easy

Author

Vincenzo Librandi, Nov 01 2011

Status

approved