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A165232 a(0)=1, a(1)=9, a(n)=18*a(n-1)-9*a(n-2) for n>1 . 1
1, 9, 153, 2673, 46737, 817209, 14289129, 249849441, 4368687777, 76387735017, 1335661040313, 23354409110481, 408358414625841, 7140261781270809, 124849486331241993 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..14.

Index entries for linear recurrences with constant coefficients, signature (18,-9)

FORMULA

G.f.: (1-9x)/(1-18x+9x^2) .

a(n)=(1/2)*{[9-6*sqrt(2)]^n+[9+6*sqrt(2)]^n}, with n>=0 [From Paolo P. Lava, Sep 16 2009]

CROSSREFS

Sequence in context: A274502 A249642 A093849 * A246641 A169958 A012017

Adjacent sequences:  A165229 A165230 A165231 * A165233 A165234 A165235

KEYWORD

nonn,easy

AUTHOR

Philippe Deléham, Sep 09 2009

STATUS

approved

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Last modified April 5 06:13 EDT 2020. Contains 333238 sequences. (Running on oeis4.)