login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A093117 a(1)=1, a(2)=15, a(n+2) = 8*a(n+1) + 21*a(n). 2
1, 15, 141, 1443, 14505, 146343, 1475349, 14875995, 149990289, 1512318207, 15248341725, 153745416147, 1550178505401, 15630081782295, 157594402871781, 1588986940402443, 16021377983526945, 161539749616666863 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n+1)/a(n) converges to 4+sqrt(37).

LINKS

Table of n, a(n) for n=1..18.

Index entries for linear recurrences with constant coefficients, signature (8,21).

FORMULA

G.f.: -(7*x+1)/(21*x^2+8*x-1) - Stefan Steinerberger, Nov 18 2005

a(n)=(1/2)*[4-sqrt(37)]^n+(11/74)*sqrt(37)*[4+sqrt(37)]^n+(1/2)*[4+sqrt(37)]^n-(11/74)*[4 -sqrt(37)]^n*sqrt(37), with n>=0 - Paolo P. Lava, Jul 08 2008

MATHEMATICA

LinearRecurrence[{8, 21}, {1, 15}, 20] (* Harvey P. Dale, Nov 03 2020 *)

CROSSREFS

Cf. A093103, A094703.

Sequence in context: A320818 A026859 A096046 * A045724 A241402 A252825

Adjacent sequences:  A093114 A093115 A093116 * A093118 A093119 A093120

KEYWORD

nonn

AUTHOR

Gary W. Adamson, May 21 2004

EXTENSIONS

More terms from Robert G. Wilson v, May 24 2004

Edited by Don Reble, Nov 04 2005

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 18 02:20 EST 2022. Contains 350410 sequences. (Running on oeis4.)