login
A083294
a(n) = (4 + (-9)^n)/5.
3
1, -1, 17, -145, 1313, -11809, 106289, -956593, 8609345, -77484097, 697356881, -6276211921, 56485907297, -508373165665, 4575358490993, -41178226418929, 370604037770369, -3335436339933313, 30018927059399825, -270170343534598417, 2431533091811385761
OFFSET
0,3
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
Cf. A083295.
Sequence in context: A181908 A233328 A364155 * A196780 A208506 A299599
KEYWORD
easy,sign
AUTHOR
Paul Barry, Apr 24 2003
STATUS
approved