A198961 4*9^n-1.

3, 35, 323, 2915, 26243, 236195, 2125763, 19131875, 172186883, 1549681955, 13947137603, 125524238435, 1129718145923, 10167463313315, 91507169819843, 823564528378595, 7412080755407363, 66708726798666275, 600378541187996483

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.: (3 + 5*x)/(1 - 10*x + 9*x^2). - Vincenzo Librandi, Jan 03 2013

Mathematica

CoefficientList[Series[(3 + 5 x)/(1 - 10 x + 9 x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 03 2013 *)

Prog

(Magma) [4*9^n-1: n in [0..20]];

Crossrefs

Sequence in context: A121078 A289950 A308033 * A112488 A221922 A260586

Adjacent sequences: A198958 A198959 A198960 * A198962 A198963 A198964

Keyword

nonn,easy

Author

Vincenzo Librandi, Nov 01 2011

Status

approved