A020405 Numbers k such that the continued fraction for sqrt(k) has period 66.

1699, 2181, 2347, 2371, 2452, 2761, 3076, 3789, 4003, 4169, 4291, 4363, 4456, 4694, 4915, 4987, 5074, 5137, 5201, 5347, 5636, 5651, 5899, 5924, 6041, 6259, 6331, 6634, 6717, 6736, 6884, 7142, 7179, 7198, 7459, 7547, 7556, 7651, 7961, 8079, 8201, 8331

Offset

1,1

Links

Table of n, a(n) for n=1..42.

Mathematica

cf66Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], {1}, Length[ ContinuedFraction[ s] [[2]]]]==66]; Select[Range[9000], cf66Q] (* Harvey P. Dale, Mar 27 2016 *)

Crossrefs

Cf. A003285.

Sequence in context: A237845 A340170 A083610 * A091368 A356213 A263344

Adjacent sequences: A020402 A020403 A020404 * A020406 A020407 A020408

Keyword

nonn

Author

David W. Wilson

Status

approved