A042643 Denominators of continued fraction convergents to sqrt(851).

1, 5, 6, 29, 64, 477, 541, 4264, 9069, 40540, 49609, 288585, 16787539, 84226280, 101013819, 488281556, 1077576931, 8031320073, 9108897004, 71793599101, 152696095206, 682577979925, 835274075131, 4858948355580, 282654278698771, 1418130341849435

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, 0, 16837148, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).

Formula

a(n) = 16837148*a(n-12) - a(n-24) for n>23. - Vincenzo Librandi, Jan 26 2014

Mathematica

Denominator[Convergents[Sqrt[851], 30]] (* Vincenzo Librandi, Jan 26 2014 *)

Prog

(Magma) I:=[1, 5, 6, 29, 64, 477, 541, 4264, 9069, 40540, 49609, 288585, 16787539, 84226280, 101013819, 488281556, 1077576931, 8031320073, 9108897004, 71793599101, 152696095206, 682577979925, 835274075131, 4858948355580]; [n le 24 select I[n] else 16837148*Self(n-12)-Self(n-24): n in [1..40]]; // Vincenzo Librandi, Jan 26 2014

Crossrefs

Cf. A040821, A042642.

Sequence in context: A041011 A152118 A041056 * A047179 A166023 A137762

Adjacent sequences: A042640 A042641 A042642 * A042644 A042645 A042646

Keyword

nonn,frac,easy

Author

N. J. A. Sloane.

Extensions

More terms from Vincenzo Librandi, Jan 26 2014

Status

approved