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A147841 a(n)=11*a(n-1)-9*a(n-2), a(0)=1, a(1)=9 . 2
1, 9, 90, 909, 9189, 92898, 939177, 9494865, 95990922, 970446357, 9810991629, 99186890706, 1002756873105, 10137643587801, 102489267607866, 1036143151396317, 10475171256888693, 105901595463208770 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..17.

FORMULA

a(n)=Sum_{k, 0<=k<=n}A147703(n,k)*8^k . G.f.: (1-2x)/(1-11x+9*x^2).

a(n)=(1/2)*[(11/2)-(1/2)*sqrt(85)]^n-(7/170)*[(11/2)-(1/2)*sqrt(85)]^n*sqrt(85)+(7/170)*sqrt(85) *[(11/2)+(1/2)*sqrt(85)]^n+(1/2)*[(11/2)+(1/2)*sqrt(85)]^n, with n>=0 [From Paolo P. Lava, Nov 18 2008]

a(n)= ((85-7*sqrt(85))/170)*(5.5-0.5*sqrt(85))^n+((85+7*sqrt(85))/170)*(5.5+0.5*sqrt(85))^n [From Richard Choulet, Nov 19 2008]

CROSSREFS

Sequence in context: A173480 A052268 A155199 * A036258 A098399 A143079

Adjacent sequences:  A147838 A147839 A147840 * A147842 A147843 A147844

KEYWORD

nonn

AUTHOR

Philippe Deléham, Nov 14 2008

EXTENSIONS

Corrected entries. - Paolo P. Lava, Nov 18 2008

STATUS

approved

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Last modified October 25 09:31 EDT 2014. Contains 248518 sequences.