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A042327 Denominators of continued fraction convergents to sqrt(690). 2
1, 3, 4, 11, 15, 56, 2927, 8837, 11764, 32365, 44129, 164752, 8611233, 25998451, 34609684, 95217819, 129827503, 484700328, 25334244559, 76487434005, 101821678564, 280130791133, 381952469697, 1425988200224, 74533338881345, 225026004844259 (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 (0,0,0,0,0,2942,0,0,0,0,0,-1).

FORMULA

G.f.: -(x^10-3*x^9+4*x^8-11*x^7+15*x^6-56*x^5-15*x^4-11*x^3-4*x^2-3*x-1) / (x^12-2942*x^6+1). - Colin Barker, Dec 07 2013

MAPLE

convert(sqrt(690), confrac, 30, cvgts): denom(cvgts); # Wesley Ivan Hurt, Dec 07 2013

MATHEMATICA

Denominator/@Convergents[Sqrt[690], 30]  (* Harvey P. Dale, Apr 21 2011 *)

CoefficientList[Series[-(x^10 - 3 x^9 + 4 x^8 - 11 x^7 + 15 x^6 - 56 x^5 - 15 x^4 - 11 x^3 - 4 x^2 - 3 x - 1)/(x^12 - 2942 x^6 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 20 2014 *)

CROSSREFS

Cf. A042326, A040663.

Sequence in context: A002530 A042709 A231067 * A046114 A116654 A041020

Adjacent sequences:  A042324 A042325 A042326 * A042328 A042329 A042330

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Dec 07 2013

STATUS

approved

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Last modified March 26 18:36 EDT 2019. Contains 321511 sequences. (Running on oeis4.)