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A041835 Denominators of continued fraction convergents to sqrt(438). 2
1, 1, 13, 14, 573, 587, 7617, 8204, 335777, 343981, 4463549, 4807530, 196764749, 201572279, 2615632097, 2817204376, 115303807137, 118121011513, 1532755945293, 1650876956806, 67567834217533, 69218711174339, 898192368309601, 967411079483940 (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, 586, 0, 0, 0, -1).

FORMULA

G.f.: -(x^2-x-1)*(x^4+14*x^2+1) / (x^8-586*x^4+1). - Colin Barker, Nov 25 2013

a(n) = 586*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Dec 25 2013

MATHEMATICA

Denominator[Convergents[Sqrt[438], 30]] (* Vincenzo Librandi, Dec 25 2013 *)

LinearRecurrence[{0, 0, 0, 586, 0, 0, 0, -1}, {1, 1, 13, 14, 573, 587, 7617, 8204}, 30] (* Harvey P. Dale, Oct 25 2015 *)

PROG

(MAGMA) I:=[1, 1, 13, 14, 573, 587, 7617, 8204]; [n le 8 select I[n] else 586*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 25 2013

CROSSREFS

Cf. A041834, A040417.

Sequence in context: A041360 A041361 A041362 * A042505 A156371 A229957

Adjacent sequences:  A041832 A041833 A041834 * A041836 A041837 A041838

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 25 2013

STATUS

approved

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Last modified November 16 02:33 EST 2018. Contains 317252 sequences. (Running on oeis4.)