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A042203 Denominators of continued fraction convergents to sqrt(627). 2
1, 25, 1251, 31300, 1566251, 39187575, 1960945001, 49062812600, 2455101575001, 61426602187625, 3073785210956251, 76906056876093900, 3848376629015651251, 96286321782267375175, 4818164465742384410001, 120550397965341877625200, 6032338062732836265670001 (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 (0,1252,0,-1).

FORMULA

G.f.: -(x^2 - 25*x - 1) / (x^4 - 1252*x^2 + 1). - Colin Barker, Dec 04 2013

a(n) = 1252*a(n-2) - a(n-4) for n > 3. - Vincenzo Librandi, Jan 16 2014

MATHEMATICA

Denominator[Convergents[Sqrt[627], 30]] (* Vincenzo Librandi, Jan 16 2014 *)

PROG

(MAGMA) I:=[1, 25, 1251, 31300]; [n le 4 select I[n] else 1252*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Jan 16 2014

CROSSREFS

Cf. A042202, A040601.

Sequence in context: A181719 A096330 A174751 * A042200 A104593 A046910

Adjacent sequences:  A042200 A042201 A042202 * A042204 A042205 A042206

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Colin Barker, Dec 04 2013

STATUS

approved

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Last modified April 22 07:26 EDT 2021. Contains 343163 sequences. (Running on oeis4.)