A020388 Numbers k such that the continued fraction for sqrt(k) has period 49.

1021, 1597, 2617, 2746, 2861, 3041, 3881, 4049, 6469, 6737, 8497, 9677, 9970, 10049, 10181, 11114, 12829, 12973, 14426, 14842, 15145, 16141, 16277, 18265, 19357, 19385, 20605, 21002, 22738, 24842, 26002, 26489, 26938, 27733, 28922, 29362, 29789, 30025

Offset

1,1

Links

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

Mathematica

cf49Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Length[ ContinuedFraction[ s] [[2]]]]==49]; Select[Range[31000], cf49Q] (* Harvey P. Dale, Mar 31 2018 *)

Crossrefs

Sequence in context: A179033 A082059 A081633 * A362361 A306596 A287639

Adjacent sequences: A020385 A020386 A020387 * A020389 A020390 A020391

Keyword

nonn

Author

David W. Wilson

Status

approved