A020379 Numbers k such that the continued fraction for sqrt(k) has period 40.

526, 589, 718, 721, 862, 1399, 1401, 1468, 1661, 2229, 2428, 2575, 2606, 2681, 2766, 2818, 2872, 2879, 2942, 3064, 3084, 3177, 3289, 3322, 3415, 3516, 3623, 3712, 3904, 3914, 3982, 4024, 4135, 4159, 4162, 4236, 4288, 4316, 4399, 4577, 4684, 4717, 4748

Offset

1,1

Links

Table of n, a(n) for n=1..43.

Mathematica

cfp40Q[n_]:=Module[{c=Sqrt[n]}, !IntegerQ[c]&&Length[ContinuedFraction[c] [[2]]]==40]; Select[Range[5000], cfp40Q] (* Harvey P. Dale, Mar 25 2012 *)

Crossrefs

Cf. A003285.

Sequence in context: A204692 A168308 A294984 * A251022 A251108 A204472

Adjacent sequences: A020376 A020377 A020378 * A020380 A020381 A020382

Keyword

nonn

Author

David W. Wilson

Status

approved