OFFSET
0,2
LINKS
Paolo Xausa, Table of n, a(n) for n = 0..1000
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.: exp(9*x)-exp(8*x)+exp(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
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Jan 31 2009
STATUS
approved