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A042111 Denominators of continued fraction convergents to sqrt(580). 2
1, 12, 577, 6936, 333505, 4008996, 192765313, 2317192752, 111418017409, 1339333401660, 64399421297089, 774132388966728, 37222754091700033, 447447181489367124, 21514687465581321985, 258623696768465230944, 12435452132351912407297, 149484049284991414118508 (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 (0,578,0,-1).

FORMULA

G.f.: -(x^2-12*x-1) / ((x^2-24*x-1)*(x^2+24*x-1)). - Colin Barker, Dec 02 2013

a(n) = 578*a(n-2) - a(n-4) for n>3. - Vincenzo Librandi, Jan 15 2014

MATHEMATICA

Denominator[Convergents[Sqrt[580], 30]] (* Vincenzo Librandi, Jan 15 2014 *)

PROG

(MAGMA) I:=[1, 12, 577, 6936]; [n le 4 select I[n] else 578*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Jan 15 2014

CROSSREFS

Cf. A042110, A040555.

Sequence in context: A283490 A159722 A307948 * A159644 A217390 A219103

Adjacent sequences:  A042108 A042109 A042110 * A042112 A042113 A042114

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Dec 02 2013

STATUS

approved

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Last modified November 28 13:47 EST 2021. Contains 349413 sequences. (Running on oeis4.)