A041405 Denominators of continued fraction convergents to sqrt(217).

1, 1, 3, 4, 11, 15, 26, 249, 1022, 9447, 10469, 19916, 50301, 70217, 190735, 260952, 7497391, 7758343, 23014077, 30772420, 84558917, 115331337, 199890254, 1914343623, 7857264746, 72629726337

Offset

0,3

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7688126, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).

Formula

a(n) = 7688126*a(n-16) - a(n-32) for n>31. [Bruno Berselli, Dec 18 2013]

Mathematica

Denominator[Convergents[Sqrt[217], 30]] (* Harvey P. Dale, Mar 20 2012 *)

Crossrefs

Cf. A041404.

Sequence in context: A249650 A114951 A085368 * A042483 A378260 A002530

Adjacent sequences: A041402 A041403 A041404 * A041406 A041407 A041408

Keyword

nonn,frac,easy

Author

N. J. A. Sloane.

Status

approved