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A042711 Denominators of continued fraction convergents to sqrt(885). 2
1, 1, 3, 4, 235, 239, 713, 952, 55929, 56881, 169691, 226572, 13310867, 13537439, 40385745, 53923184, 3167930417, 3221853601, 9611637619, 12833491220, 753954128379, 766787619599, 2287529367577, 3054316987176, 179437914623785, 182492231610961 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 238, 0, 0, 0, -1).

FORMULA

G.f.: -(x^2-x-1)*(x^4+4*x^2+1) / (x^8-238*x^4+1). - Colin Barker, Dec 22 2013

a(n) = 238*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Dec 22 2013

MATHEMATICA

Denominator[Convergents[Sqrt[885], 30]] (* Vincenzo Librandi, Dec 22 2013 *)

PROG

(MAGMA) I:=[1, 1, 3, 4, 235, 239, 713, 952]; [n le 8 select I[n] else 238*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 22 2013

CROSSREFS

Cf. A042710, A040855.

Sequence in context: A012861 A042485 A111315 * A195566 A304150 A305505

Adjacent sequences:  A042708 A042709 A042710 * A042712 A042713 A042714

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Dec 22 2013

STATUS

approved

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Last modified February 18 09:28 EST 2019. Contains 320249 sequences. (Running on oeis4.)