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A041681 Denominators of continued fraction convergents to sqrt(359). 2
1, 1, 18, 19, 702, 721, 12959, 13680, 505439, 519119, 9330462, 9849581, 363915378, 373764959, 6717919681, 7091684640, 262018566721, 269110251361, 4836892839858, 5106003091219, 188653004123742, 193759007214961, 3482556126778079, 3676315133993040 (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, 720, 0, 0, 0, -1).

FORMULA

G.f.: -(x^2-x-1)*(x^4+19*x^2+1) / (x^8-720*x^4+1). - Colin Barker, Nov 21 2013

a(n) = 720*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Dec 22 2013

MATHEMATICA

Denominator[Convergents[Sqrt[359], 30]] (* Harvey P. Dale, Oct 08 2011 *)

CoefficientList[Series[-(x^2 - x-1) (x^4 + 19 x^2 + 1)/(x^8 - 720 x^4 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 22 2013 *)

PROG

(MAGMA) I:=[1, 1, 18, 19, 702, 721, 12959, 13680]; [n le 8 select I[n] else 720*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 22 2013

CROSSREFS

Cf. A041680, A040340.

Sequence in context: A197352 A056083 A041680 * A041682 A265946 A027888

Adjacent sequences:  A041678 A041679 A041680 * A041682 A041683 A041684

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 21 2013

STATUS

approved

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Last modified December 14 17:53 EST 2019. Contains 329979 sequences. (Running on oeis4.)