A199564 6*9^n+1.

7, 55, 487, 4375, 39367, 354295, 3188647, 28697815, 258280327, 2324522935, 20920706407, 188286357655, 1694577218887, 15251194969975, 137260754729767, 1235346792567895, 11118121133111047, 100063090197999415, 900567811781994727

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).

G.f.: (7-15*x)/((1-x)*(1-9*x)).

Mathematica

6*9^Range[0, 20]+1 (* or *) LinearRecurrence[{10, -9}, {7, 55}, 20] (* Harvey P. Dale, Apr 16 2014 *)

Prog

(Magma) [6*9^n+1: n in [0..30]];

Crossrefs

Sequence in context: A108628 A116862 A096307 * A225032 A124403 A005012

Adjacent sequences: A199561 A199562 A199563 * A199565 A199566 A199567

Keyword

nonn,easy

Author

Vincenzo Librandi, Nov 08 2011

Status

approved