login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 A264914

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 4 23:10 EST 2016. Contains 278755 sequences.