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A041773 Denominators of continued fraction convergents to sqrt(407). 2
1, 5, 6, 17, 23, 132, 5303, 26647, 31950, 90547, 122497, 703032, 28243777, 141921917, 170165694, 482253305, 652418999, 3744348300, 150426350999, 755876103295, 906302454294, 2568481011883, 3474783466177, 19942398342768, 801170717176897, 4025795984227253 (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, 5326, 0, 0, 0, 0, 0, -1).

FORMULA

G.f.: -(x^10-5*x^9+6*x^8-17*x^7+23*x^6-132*x^5-23*x^4-17*x^3-6*x^2-5*x-1) / (x^12-5326*x^6+1). - Colin Barker, Nov 24 2013

a(n) = 5326*a(n-6) - a(n-12) for n>11. - Vincenzo Librandi, Dec 24 2013

MATHEMATICA

Denominator[Convergents[Sqrt[407], 40]] (* Harvey P. Dale, Jul 13 2012 *)

CoefficientList[Series[-(x^10 - 5 x^9 + 6 x^8 - 17 x^7 + 23 x^6 - 132 x^5 - 23 x^4 - 17 x^3 - 6 x^2 - 5 x - 1)/(x^12 - 5326 x^6 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 24 2013 *)

PROG

(MAGMA) I:=[1, 5, 6, 17, 23, 132, 5303, 26647, 31950, 90547, 122497, 703032]; [n le 12 select I[n] else 5326*Self(n-6)-Self(n-12): n in [1..50]]; // Vincenzo Librandi, Dec 24 2013

CROSSREFS

Cf. A041772, A040386.

Sequence in context: A035595 A099571 A041997 * A041054 A297980 A120034

Adjacent sequences:  A041770 A041771 A041772 * A041774 A041775 A041776

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified May 24 15:25 EDT 2019. Contains 323532 sequences. (Running on oeis4.)