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A042081 Denominators of continued fraction convergents to sqrt(564). 2
1, 1, 3, 4, 187, 191, 569, 760, 35529, 36289, 108107, 144396, 6750323, 6894719, 20539761, 27434480, 1282525841, 1309960321, 3902446483, 5212406804, 243673159467, 248885566271, 741444292009, 990329858280, 46296617772889, 47286947631169 (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 (0,0,0,190,0,0,0,-1).

FORMULA

G.f.: -(x^2-x-1)*(x^4+4*x^2+1) / (x^8-190*x^4+1). - Colin Barker, Dec 01 2013

a(n) = 190*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Jan 14 2014

MATHEMATICA

Denominator[Convergents[Sqrt[564], 30]] (* Harvey P. Dale, Nov 08 2011 *)

CoefficientList[Series[(1 + x - x^2) (x^4 + 4 x^2 + 1)/(x^8 - 190 x^4 + 1), {x, 0, 40}], x] (* Vincenzo Librandi, Jan 14 2014 *)

PROG

(MAGMA) I:=[1, 1, 3, 4, 187, 191, 569, 760]; [n le 8 select I[n] else 190*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Jan 14 2014

CROSSREFS

Cf. A042080, A040540.

Sequence in context: A156513 A082213 A097172 * A245456 A042275 A012861

Adjacent sequences:  A042078 A042079 A042080 * A042082 A042083 A042084

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Dec 01 2013

STATUS

approved

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Last modified October 18 12:18 EDT 2019. Contains 328160 sequences. (Running on oeis4.)