A041619 Denominators of continued fraction convergents to sqrt(328).

1, 9, 325, 2934, 105949, 956475, 34539049, 311807916, 11259624025, 101648424141, 3670602893101, 33137074462050, 1196605283526901, 10802584626204159, 390089651826876625, 3521609451068093784

Offset

0,2

Links

Andrew Howroyd, Table of n, a(n) for n = 0..200 (terms 0..56 from Vincenzo Librandi)

Index entries for linear recurrences with constant coefficients, signature (0,326,0,-1).

Formula

From Colin Barker, Jul 16 2012: (Start)

a(n) = 326*a(n-2)-a(n-4).

G.f.: -(x^2-9*x-1)/((x^2-18*x-1)*(x^2+18*x-1)).

(End)

Mathematica

Denominator[Convergents[Sqrt[328], 30]] (* Harvey P. Dale, Mar 01 2012 *)
CoefficientList[Series[- (x^2 - 9 x - 1)/((x^2 - 18 x - 1)(x^2 + 18 x - 1)), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 25 2013 *)

Crossrefs

Cf. A041618.

Sequence in context: A211091 A124070 A203763 * A111968 A289196 A266907

Adjacent sequences: A041616 A041617 A041618 * A041620 A041621 A041622

Keyword

nonn,cofr,frac,easy

Author

N. J. A. Sloane

Status

approved