A020409 Numbers k such that the continued fraction for sqrt(k) has period 70.

1366, 1579, 1684, 2707, 3189, 3371, 3446, 3826, 3851, 4132, 4612, 4869, 4881, 4948, 5169, 5464, 5563, 5867, 6313, 6721, 6772, 7366, 7478, 7876, 7907, 7918, 8006, 8122, 8152, 8198, 8449, 8564, 8754, 8950, 9053, 9188, 9538, 9787, 9814, 9923, 9994, 10198

Offset

1,1

Links

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

Mathematica

cf70Q[n_]:=Module[{sr=Sqrt[n]}, !IntegerQ[sr]&&Length[ContinuedFraction[ sr][[2]]]==70]; Select[Range[11000], cf70Q] (* Harvey P. Dale, Jul 24 2012 *)

Crossrefs

Cf. A003285.

Sequence in context: A295466 A292780 A180089 * A231268 A192823 A221932

Adjacent sequences: A020406 A020407 A020408 * A020410 A020411 A020412

Keyword

nonn

Author

David W. Wilson

Status

approved