A155666 9^n-8^n+1.

1, 2, 18, 218, 2466, 26282, 269298, 2685818, 26269506, 253202762, 2413042578, 22791125018, 213710059746, 1992110014442, 18478745943858, 170706760005818, 1571545212141186, 14425381885981322, 132080236787517138

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)=2 - Vincenzo Librandi, Jul 21 2010

Mathematica

Table[9^n-8^n+1, {n, 0, 20}] (* or *) LinearRecurrence[{18, -89, 72}, {1, 2, 18}, 20] (* Harvey P. Dale, Aug 16 2015 *)

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, A155663, A155664, A155665.

Sequence in context: A052726 A217239 A279045 * A355723 A227934 A349652

Adjacent sequences: A155663 A155664 A155665 * A155667 A155668 A155669

Keyword

nonn,easy

Author

Mohammad K. Azarian, Jan 31 2009

Status

approved