A198859 2*9^n-1.

1, 17, 161, 1457, 13121, 118097, 1062881, 9565937, 86093441, 774840977, 6973568801, 62762119217, 564859072961, 5083731656657, 45753584909921, 411782264189297, 3706040377703681, 33354363399333137, 300189270593998241

Offset

0,2

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.: (7*x+1)/(9*x^2-10*x+1). - Harvey P. Dale, Jan 01 2013

Mathematica

2*9^Range[0, 30]-1 (* or *) LinearRecurrence[{10, -9}, {1, 17}, 30] (* Harvey P. Dale, Jan 01 2013 *)

Prog

(Magma) [2*9^n-1: n in [0..20]]

Crossrefs

Sequence in context: A125380 A126538 A164746 * A160295 A125645 A372965

Adjacent sequences: A198856 A198857 A198858 * A198860 A198861 A198862

Keyword

nonn,easy

Author

Vincenzo Librandi, Nov 01 2011

Status

approved