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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A042405 Denominators of continued fraction convergents to sqrt(730). 2
1, 54, 2917, 157572, 8511805, 459795042, 24837444073, 1341681774984, 72475653293209, 3915026959608270, 211483931472139789, 11424047326455156876, 617110039560050611093, 33335366183569188155898, 1800726883952296211029585, 97272587099607564583753488 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

Tanya Khovanova, Recursive Sequences

Index entries for linear recurrences with constant coefficients, signature (54, 1).

FORMULA

a(n) = F(n, 54), the n-th Fibonacci polynomial evaluated at x=54. - T. D. Noe, Jan 19 2006

a(n) = 54*a(n-1)+a(n-2) for n>1; a(0)=1, a(1)=54. G.f.: 1/(1-54*x-x^2). [Philippe Deléham, Nov 23 2008]

a(n) = (1/2)*((27+sqrt(730))^n+(27-sqrt(730))^n)+(27/1460)*sqrt(730)*((27+sqrt(730))^n-(27 -sqrt(730))^n). [Paolo P. Lava, Dec 01 2008]

MATHEMATICA

a=0; lst = {}; s = 0; Do[a = s-(a-1); AppendTo[lst, a]; s+ = a*54, {n, 3*4!}]; lst (* Vladimir Joseph Stephan Orlovsky, Nov 03 2009 *)

Denominator[Convergents[Sqrt[730], 30]] (* Vincenzo Librandi, Jan 21 2014 *)

CROSSREFS

Cf. A042404.

Sequence in context: A207093 A188990 A189200 * A187304 A212705 A046199

Adjacent sequences:  A042402 A042403 A042404 * A042406 A042407 A042408

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

a(15) from Colin Barker, Dec 11 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified June 26 23:21 EDT 2017. Contains 288777 sequences.