A198687 5*7^n-1.

4, 34, 244, 1714, 12004, 84034, 588244, 4117714, 28824004, 201768034, 1412376244, 9886633714, 69206436004, 484445052034, 3391115364244, 23737807549714, 166164652848004, 1163152569936034, 8142067989552244, 56994475926865714

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

G.f.:(4+2*x)/((1-x)*(1-7*x)). - Vincenzo Librandi, Jul 06 2012

Mathematica

CoefficientList[Series[(4+2*x)/((1-x)*(1-7*x)), {x, 0, 40}], x] (* Vincenzo Librandi, Jul 06 2012 *)
LinearRecurrence[{8, -7}, {4, 34}, 20] (* Harvey P. Dale, Jul 23 2024 *)

Prog

(Magma) [5*7^n-1: n in [0..30]]

Crossrefs

Cf. A048473, A081655, A198480, A198647.

Sequence in context: A197075 A085695 A049293 * A116430 A216239 A335667

Adjacent sequences: A198684 A198685 A198686 * A198688 A198689 A198690

Keyword

nonn,easy

Author

Vincenzo Librandi, Oct 29 2011

Status

approved