OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (16,-69,54).
FORMULA
G.f.: 1/(1-9*x)-1/(1-6*x)+1/(1-x). E.g.f.: e^(9*x)-e^(6*x)+e^x.
a(n)=15*a(n-1)-54*a(n-2)+40 with a(0)=1, a(1)=4 - Vincenzo Librandi, Jul 21 2010
PROG
(PARI) a(n)=9^n-6^n+1^n \\ Charles R Greathouse IV, Jun 11 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Jan 31 2009
STATUS
approved