A020386 Numbers k such that the continued fraction for sqrt(k) has period 47.

1069, 1993, 2801, 2969, 3589, 3865, 4241, 4289, 4337, 4618, 5981, 6089, 6109, 6173, 6833, 7457, 8629, 9194, 11909, 12113, 14666, 15353, 15973, 16066, 17002, 17009, 19450, 19858, 21346, 21722, 24370, 25189, 26485, 26861, 29597, 30269, 30986, 31090

Offset

1,1

Links

Table of n, a(n) for n=1..38.

Mathematica

cf47Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Length[ContinuedFraction[s][[2]]]]==47]; Select[Range[32000], cf47Q] (* Harvey P. Dale, Sep 27 2024 *)

Crossrefs

Cf. A003285.

Sequence in context: A289702 A095673 A252569 * A236870 A345904 A252256

Adjacent sequences: A020383 A020384 A020385 * A020387 A020388 A020389

Keyword

nonn

Author

David W. Wilson

Status

approved