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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A042779 Denominators of continued fraction convergents to sqrt(920). 2
1, 3, 181, 546, 32941, 99369, 5995081, 18084612, 1091071801, 3291300015, 198569072701, 598998518118, 36138480159781, 109014438997461, 6577004820007441, 19840028899019784, 1196978738761194481, 3610776245182603227, 217843553449717388101, 657141436594334767530 (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 (0,182,0,-1).

FORMULA

G.f.: -(x^2-3*x-1) / (x^4-182*x^2+1). - Colin Barker, Dec 23 2013

a(n) = 182*a(n-2) - a(n-4) for n>3. - Vincenzo Librandi, Jan 29 2014

MATHEMATICA

Denominator[Convergents[Sqrt[920], 30]] (* Harvey P. Dale, May 03 2012 *)

PROG

(MAGMA) I:=[1, 3, 181, 546]; [n le 4 select I[n] else 182*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Jan 29 2014

CROSSREFS

Cf. A042778, A040889.

Sequence in context: A093434 A053291 A013519 * A103503 A203562 A198701

Adjacent sequences:  A042776 A042777 A042778 * A042780 A042781 A042782

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Dec 23 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 21 23:29 EST 2019. Contains 320381 sequences. (Running on oeis4.)