A020407 Numbers k such that the continued fraction for sqrt(k) has period 68.

1879, 1951, 2239, 3079, 3244, 3991, 4231, 4567, 4689, 4871, 5361, 5553, 5937, 5998, 6044, 6064, 6295, 6304, 6346, 6535, 6719, 6906, 7276, 7564, 7615, 7629, 8423, 8444, 8748, 8764, 8894, 8896, 8959, 9007, 9117, 9223, 9276, 9358, 9564, 9741, 9784, 10078

Offset

1,1

Links

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

Mathematica

cf68Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Length[ ContinuedFraction[ s][[2]]]]==68]; Select[Range[11000], cf68Q] (* Harvey P. Dale, Aug 20 2015 *)

Crossrefs

Cf. A003285.

Sequence in context: A127410 A237570 A045201 * A320719 A358147 A235193

Adjacent sequences: A020404 A020405 A020406 * A020408 A020409 A020410

Keyword

nonn

Author

David W. Wilson

Status

approved