A155670 11^n+9^n-1^n.

1, 19, 201, 2059, 21201, 220099, 2303001, 24270139, 257405601, 2745368179, 29424209001, 316692730219, 3420857913201, 37064577972259, 402626626038201, 4383139301510299, 47802750052424001, 522124210198960339

Offset: 0

Author

Mohammad K. Azarian, Feb 01 2009

Keywords

• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (21,-119,99).

Crossrefs

A155646, A155647, A155648, A155649, A155650, A155651, A155652, A155653, A155654, A155655, A155656, A155657, A155658, A155659, A155660, A155661, A155662, A155663, A155664, A155665, A155666, A155667, A155668, A155669

Programs

Mathematica

Table[11^n+9^n-1^n, {n,0,30}] (* Harvey P. Dale, Mar 26 2011 *)

PARI

a(n)=11^n+9^n-1^n \\ Charles R Greathouse IV, Oct 16 2015

Formula

G.f.: 1/(1-11*x)+1/(1-9*x)-1/(1-x). E.g.f.: e^(11*x)+e^(9*x)-e^x.

a(n)=20*a(n-1)-99*a(n-2)-80 with a(0)=1, a(1)=19 - Vincenzo Librandi, Jul 21 2010