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!)
A041577 Denominators of continued fraction convergents to sqrt(306). 2
1, 2, 69, 140, 4829, 9798, 337961, 685720, 23652441, 47990602, 1655332909, 3358656420, 115849651189, 235057958798, 8107820250321, 16450698459440, 567431567871281, 1151313834202002, 39712101930739349, 80575517695680700, 2779279703583883149 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (0, 70, 0, -1).

FORMULA

G.f.: -(x^2-2*x-1) / (x^4-70*x^2+1). - Colin Barker, Nov 19 2013

a(n) = 70*a(n-2) - a(n-4) for n>3. - Vincenzo Librandi, Dec 20 2013

MATHEMATICA

Denominator[Convergents[Sqrt[306], 30]] (* Vincenzo Librandi, Dec 20 2013 *)

PROG

(MAGMA) I:=[1, 2, 69, 140]; [n le 4 select I[n] else 70*Self(n-2)-Self(n-4): n in [1..40]]; // Vincenzo Librandi, Dec 20 2013

CROSSREFS

Cf. A041576, A040288.

Sequence in context: A283038 A264457 A246744 * A180085 A321244 A224506

Adjacent sequences:  A041574 A041575 A041576 * A041578 A041579 A041580

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Additional term from Colin Barker, Nov 19 2013

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 18 23:31 EDT 2022. Contains 353826 sequences. (Running on oeis4.)