A198962 5*9^n-1.

4, 44, 404, 3644, 32804, 295244, 2657204, 23914844, 215233604, 1937102444, 17433922004, 156905298044, 1412147682404, 12709329141644, 114383962274804, 1029455660473244, 9265100944259204, 83385908498332844, 750473176484995604

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) = 4*A138894(n).

a(n) = 9*a(n-1)+8, n>0.

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

G.f. ( 4+4*x ) / ( (9*x-1)*(x-1) ). - R. J. Mathar, Nov 01 2011

Mathematica

5*9^Range[0, 30]-1 (* or *) LinearRecurrence[{10, -9}, {4, 44}, 30] (* Harvey P. Dale, Oct 20 2019 *)

Prog

(Magma) [5*9^n-1: n in [0..20]]

Crossrefs

Sequence in context: A297384 A178294 A043039 * A002754 A187870 A216272

Adjacent sequences: A198959 A198960 A198961 * A198963 A198964 A198965

Keyword

nonn,easy

Author

Vincenzo Librandi, Nov 01 2011

Status

approved