A042537 Denominators of continued fraction convergents to sqrt(797).

1, 4, 13, 173, 186, 917, 3854, 4771, 65877, 202402, 875485, 49229562, 197793733, 642610761, 8551733626, 9194344387, 45329111174, 190510789083, 235839900257, 3256429492424, 10005128377529, 43276943002540, 2433513936519769, 9777332689081616

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, 0, 0, 0, 0, 0, 0, 0, 0, 0, 49431964, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).

Formula

a(n) = 49431964*a(n-11) + a(n-22) for n>21. - Vincenzo Librandi, Jan 23 2014

Mathematica

Denominator[Convergents[Sqrt[797], 30]] (* Harvey P. Dale, Sep 30 2012 *)

Prog

(Magma) I:=[1, 4, 13, 173, 186, 917, 3854, 4771, 65877, 202402, 875485, 49229562, 197793733, 642610761, 8551733626, 9194344387, 45329111174, 190510789083, 235839900257, 3256429492424, 10005128377529, 43276943002540]; [n le 22 select I[n] else 49431964*Self(n-11)+Self(n-22): n in [1..30]]; // Vincenzo Librandi, Jan 23 2014

Crossrefs

Cf. A040768, A042536.

Sequence in context: A198159 A322659 A397016 * A220038 A394318 A132512

Adjacent sequences: A042534 A042535 A042536 * A042538 A042539 A042540

Keyword

nonn,frac,easy

Author

N. J. A. Sloane

Extensions

More terms from Vincenzo Librandi, Jan 23 2014

Status

approved