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A041403 Denominators of continued fraction convergents to sqrt(216). 2
1, 1, 3, 10, 23, 33, 947, 980, 2907, 9701, 22309, 32010, 918589, 950599, 2819787, 9409960, 21639707, 31049667, 891030383, 922080050, 2735190483, 9127651499, 20990493481, 30118144980, 864298552921, 894416697901, 2653131948723, 8853812544070, 20360757036863 (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 (0,0,0,0,0,970,0,0,0,0,0,-1).

FORMULA

G.f.: -(x^10 -x^9 +3*x^8 -10*x^7 +23*x^6 -33*x^5 -23*x^4 -10*x^3 -3*x^2 -x -1) / ((x^4 -10*x^2 +1)*(x^8 +10*x^6 +99*x^4 +10*x^2 +1)). - Colin Barker, Nov 17 2013

a(n) = 970*a(n-6) - a(n-12) for n>11. - Vincenzo Librandi, Dec 17 2013

MATHEMATICA

Denominator[Convergents[Sqrt[216], 30]] (* Vincenzo Librandi, Dec 17 2013 *)

PROG

(MAGMA) I:=[1, 1, 3, 10, 23, 33, 947, 980, 2907, 9701, 22309, 32010]; [n le 12 select I[n] else 970*Self(n-6)-Self(n-12): n in [1..40]]; // Vincenzo Librandi, Dec 17 2013

CROSSREFS

Cf. A041402, A040201.

Sequence in context: A292921 A270470 A166119 * A271740 A077126 A172113

Adjacent sequences:  A041400 A041401 A041402 * A041404 A041405 A041406

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 17 2013

STATUS

approved

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Last modified February 16 12:48 EST 2019. Contains 320163 sequences. (Running on oeis4.)