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A042669 Denominators of continued fraction convergents to sqrt(864). 2
1, 2, 3, 5, 28, 33, 457, 490, 2907, 3397, 6304, 16005, 934594, 1885193, 2819787, 4704980, 26344687, 31049667, 429990358, 461040025, 2735190483, 3196230508, 5931420991, 15059072490, 879357625411, 1773774323312, 2653131948723, 4426906272035, 24787663308898 (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 (0,0,0,0,0,0,0,0,0,0,0,940898,0,0,0,0,0,0,0,0,0,0,0,-1).

FORMULA

G.f.: -(x^22 -2*x^21 +3*x^20 -5*x^19 +28*x^18 -33*x^17 +457*x^16 -490*x^15 +2907*x^14 -3397*x^13 +6304*x^12 -16005*x^11 -6304*x^10 -3397*x^9 -2907*x^8 -490*x^7 -457*x^6 -33*x^5 -28*x^4 -5*x^3 -3*x^2 -2*x -1) / ((x^4 -6*x^3 +13*x^2 -6*x +1)*(x^4 -10*x^2 +1)*(x^4 +10*x^2 +1)*(x^4 +6*x^3 +13*x^2 +6*x +1)*(x^8 +10*x^6 +99*x^4 +10*x^2 +1)). - Colin Barker, Dec 20 2013

a(n) = 940898*a(n-12) - a(n-24) for n>23. - Vincenzo Librandi, Dec 20 2013

MATHEMATICA

Denominator[Convergents[Sqrt[864], 30]] (* Vincenzo Librandi, Dec 20 2013 *)

PROG

(MAGMA) I:=[1, 2, 3, 5, 28, 33, 457, 490, 2907, 3397, 6304, 16005, 934594, 1885193, 2819787, 4704980, 26344687, 31049667, 429990358, 461040025, 2735190483, 3196230508, 5931420991, 15059072490]; [n le 24 select I[n] else 940898*Self(n-12)-Self(n-24): n in [1..40]]; // Vincenzo Librandi, Dec 20 2013

CROSSREFS

Cf. A042668, A040834.

Sequence in context: A141566 A247094 A078736 * A178376 A041585 A042935

Adjacent sequences:  A042666 A042667 A042668 * A042670 A042671 A042672

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Dec 20 2013

STATUS

approved

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Last modified May 16 05:56 EDT 2021. Contains 343939 sequences. (Running on oeis4.)