OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (20,-109,90).
FORMULA
G.f.: 1/(1-10*x)+1/(1-9*x)-1/(1-x). E.g.f.: e^(10*x)+e^(9*x)-e^x.
a(n)=19*a(n-1)-90*a(n-2)-72 with a(0)=1, a(1)=18 - Vincenzo Librandi, Jul 21 2010
PROG
(PARI) a(n)=10^n+9^n-1 \\ Charles R Greathouse IV, Jun 11 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Feb 01 2009
STATUS
approved