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A042275 Denominators of continued fraction convergents to sqrt(663). 2
1, 1, 3, 4, 203, 207, 617, 824, 41817, 42641, 127099, 169740, 8614099, 8783839, 26181777, 34965616, 1774462577, 1809428193, 5393318963, 7202747156, 365530676763, 372733423919, 1110997524601, 1483730948520, 75297544950601, 76781275899121 (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, 206, 0, 0, 0, -1).

FORMULA

G.f.: -(x^2-x-1)*(x^4+4*x^2+1) / (x^8-206*x^4+1). - Colin Barker, Dec 06 2013

a(n) = 206*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Jan 19 2014

MAPLE

convert(sqrt(663), confrac, 30, cvgts): denom(cvgts); # Wesley Ivan Hurt, Dec 07 2013

MATHEMATICA

Denominator[Convergents[Sqrt[663], 30]] (* Vincenzo Librandi, Jan 19 2014 *)

PROG

(MAGMA) I:=[1, 1, 3, 4, 203, 207, 617, 824]; [n le 8 select I[n] else 206*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Jan 19 2014

CROSSREFS

Cf. A042274, A040637.

Sequence in context: A097172 A042081 A245456 * A012861 A042485 A111315

Adjacent sequences:  A042272 A042273 A042274 * A042276 A042277 A042278

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Dec 06 2013

STATUS

approved

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Last modified March 20 15:43 EDT 2019. Contains 321345 sequences. (Running on oeis4.)