OFFSET
0,3
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..300
Index entries for linear recurrences with constant coefficients, signature (-8,9).
FORMULA
a(n) = (4 + (-9)^n)/5.
G.f.: (1+7*x)/((1-x)*(1+9*x)).
E.g.f.: (4*exp(x) + exp(-9*x))/5.
MATHEMATICA
(4+(-9)^Range[0, 20])/5 (* or *) LinearRecurrence[{-8, 9}, {1, -1}, 30] (* Harvey P. Dale, Sep 25 2021 *)
PROG
(Magma) [(4+(-9)^n)/5: n in [0..30]]; // Vincenzo Librandi, Jun 08 2011
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Apr 24 2003
STATUS
approved