A041843 Denominators of continued fraction convergents to sqrt(443).

1, 21, 883, 18564, 780571, 16410555, 690023881, 14506912056, 609980330233, 12824093846949, 539221921902091, 11336484453790860, 476671568981118211, 10021439433057273291, 421377127757386596433, 8858941122338175798384

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, 884, 0, -1).

Formula

G.f.: -(x^2-21*x-1) / (x^4-884*x^2+1). - Colin Barker, Nov 25 2013

a(n) = 884*a(n-2) - a(n-4) for n>3. - Vincenzo Librandi, Dec 25 2013

Mathematica

Denominator[Convergents[Sqrt[443], 30]] (* Vincenzo Librandi, Dec 25 2013 *)

Prog

(Magma) I:=[1, 21, 883, 18564]; [n le 4 select I[n] else 884*Self(n-2)-Self(n-4): n in [1..50]]; // Vincenzo Librandi, Dec 25 2013

Crossrefs

Cf. A041842, A040421.

Sequence in context: A202810 A204196 A238653 * A041840 A012793 A015305

Adjacent sequences: A041840 A041841 A041842 * A041844 A041845 A041846

Keyword

nonn,frac,easy,less

Author

N. J. A. Sloane.

Status

approved