A165759 a(n) = (7-4*7^n)/3.

1, -7, -63, -455, -3199, -22407, -156863, -1098055, -7686399, -53804807, -376633663, -2636435655, -18455049599, -129185347207, -904297430463, -6330082013255, -44310574092799, -310174018649607, -2171218130547263, -15198526913830855, -106389688396815999

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..500

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

Formula

a(n) = 7*a(n-1)-14, a(0)=1.

a(n) = 8*a(n-1) - 7*a(n-2), a(0)= 1, a(1)= -7, for n>1.

G.f.: (1-15x)/(1-8x+7x^2).

a(n) = Sum_{0<=k<=n} A112555(n,k)*(-8)^(n-k).

E.g.f.: (1/3)*(7*exp(x) - 4*exp(7*x)). - G. C. Greubel, Apr 07 2016

Mathematica

(7-4*7^Range[0, 20])/3 (* or *) LinearRecurrence[{8, -7}, {1, -7}, 30] (* Harvey P. Dale, Dec 21 2014 *)

Crossrefs

Sequence in context: A055405 A100741 A043027 * A166153 A123009 A219058

Adjacent sequences: A165756 A165757 A165758 * A165760 A165761 A165762

Keyword

easy,sign

Author

Philippe Deléham, Sep 26 2009

Extensions

Corrected and extended by Harvey P. Dale, Dec 21 2014

Status

approved