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A041697 Denominators of continued fraction convergents to sqrt(368). 2
1, 5, 11, 60, 2291, 11515, 25321, 138120, 5273881, 26507525, 58288931, 317952180, 12140471771, 61020311035, 134181093841, 731925780240, 27947360742961, 140468729495045, 308884819733051, 1684892828160300, 64334812289824451, 323358954277282555 (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 (0,0,0,2302,0,0,0,-1).

FORMULA

G.f.: -(x^2-5*x-1)*(x^4+12*x^2+1) / ((x^4-48*x^2+1)*(x^4+48*x^2+1)). - Colin Barker, Nov 22 2013

a(n) = 2302*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Dec 23 2013

MATHEMATICA

Denominator[Convergents[Sqrt[368], 30]] (* Vincenzo Librandi, Dec 23 2013 *)

LinearRecurrence[{0, 0, 0, 2302, 0, 0, 0, -1}, {1, 5, 11, 60, 2291, 11515, 25321, 138120}, 30] (* Harvey P. Dale, Nov 21 2015 *)

PROG

(MAGMA) I:=[1, 5, 11, 60, 2291, 11515, 25321, 138120]; [n le 8 select I[n] else 2302*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 23 2013

CROSSREFS

Cf. A041696, A040348.

Sequence in context: A173875 A095150 A215759 * A121170 A239322 A101209

Adjacent sequences:  A041694 A041695 A041696 * A041698 A041699 A041700

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 22 2013

STATUS

approved

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Last modified December 10 20:48 EST 2017. Contains 295856 sequences.