A198691 10*7^n-1.

9, 69, 489, 3429, 24009, 168069, 1176489, 8235429, 57648009, 403536069, 2824752489, 19773267429, 138412872009, 968890104069, 6782230728489, 47475615099429, 332329305696009, 2326305139872069, 16284135979104489, 113988951853731429

Offset

0,1

Links

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

Index entries for linear recurrences with constant coefficients, signature (8,-7).

Formula

a(n) = 7*a(n-1)+6. a(n) = 8*a(n-1)-7*a(n-2), n>1.

G.f. ( 9-3*x ) / ( (7*x-1)*(x-1) ). - R. J. Mathar, Oct 30 2011

Mathematica

10*7^Range[0, 20]-1 (* or *) LinearRecurrence[{8, -7}, {9, 69}, 20] (* Harvey P. Dale, Mar 30 2016 *)

Prog

(Magma) [10*7^n-1: n in [0..30]]

Crossrefs

Cf. A024075, A048473, A081655, A198480, A198647.

Sequence in context: A072258 A196490 A297593 * A125372 A165147 A075045

Adjacent sequences: A198688 A198689 A198690 * A198692 A198693 A198694

Keyword

nonn,easy

Author

Vincenzo Librandi, Oct 29 2011

Status

approved