A155663 9^n+8^n-1.

1, 16, 144, 1240, 10656, 91816, 793584, 6880120, 59823936, 521638216, 4560526224, 39970994200, 351149013216, 3091621642216, 27274838966064, 241075504183480, 2134495165562496, 18928981513351816, 168109033806481104

Offset

0,2

Links

Table of n, a(n) for n=0..18.

Index entries for linear recurrences with constant coefficients, signature (18,-89,72).

Formula

G.f.: 1/(1-9*x)+1/(1-8*x)-1/(1-x). E.g.f.: e^(9*x)+e^(8*x)-e^x.

a(n)=17*a(n-1)-72*a(n-2)-56 with a(0)=1, a(1)=16 - Vincenzo Librandi, Jul 21 2010

Mathematica

Table[9^n+8^n-1, {n, 0, 20}] (* or *) LinearRecurrence[{18, -89, 72}, {1, 16, 144}, 20] (* Harvey P. Dale, Jun 14 2016 *)

Prog

(PARI) a(n)=9^n+8^n-1 \\ Charles R Greathouse IV, Jun 11 2015

Crossrefs

Cf. A155646, A155647, A155648, A155649, A155650, A155651, A155652, A155653, A155654, A155655, A155656, A155657, A155658, A155659, A155660, A155661, A155662.

Sequence in context: A230971 A282524 A287168 * A077485 A131705 A203538

Adjacent sequences: A155660 A155661 A155662 * A155664 A155665 A155666

Keyword

nonn,easy

Author

Mohammad K. Azarian, Jan 31 2009

Status

approved