A041851 Denominators of continued fraction convergents to sqrt(447).

1, 7, 295, 2072, 87319, 613305, 25846129, 181536208, 7650366865, 53734104263, 2264482745911, 15905113325640, 670279242422791, 4707859810285177, 198400391274400225, 1393510598731086752, 58725845537980043809, 412474429364591393415, 17382651878850818567239

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, 296, 0, -1).

Formula

G.f.: -(x^2 -7*x -1) / (x^4 -296*x^2 +1). - Colin Barker, Nov 26 2013

a(n) = 296*a(n-2) - a(n-4) for n>3. - Vincenzo Librandi, Dec 25 2013

Mathematica

Denominator[Convergents[Sqrt[447], 30]] (* Vincenzo Librandi, Dec 25 2013 *)

Prog

(Magma) I:=[1, 7, 295, 2072]; [n le 4 select I[n] else 296*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 25 2013

Crossrefs

Cf. A041850, A040425.

Sequence in context: A160072 A137435 A220241 * A082168 A362658 A096348

Adjacent sequences: A041848 A041849 A041850 * A041852 A041853 A041854

Keyword

nonn,frac,easy

Author

N. J. A. Sloane.

Extensions

More terms from Colin Barker, Nov 26 2013

Status

approved