A031849 Period of continued fraction for sqrt(n) contains exactly 81 ones.

41827, 59599, 61771, 62875, 77851, 114091, 119695, 129823, 174031, 177331, 193483, 211579, 217663, 230263, 236567, 237703, 238067, 248811, 255547, 280135, 281695, 285112, 298915, 307739, 310991, 314843, 317531, 317615, 329203, 335443, 339607

Offset

1,1

Links

Table of n, a(n) for n=1..31.

Mathematica

cf81Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Count[ContinuedFraction[ s][[2]], 1]]==81]; Select[Range[340000], cf81Q] (* Harvey P. Dale, Feb 25 2020 *)

Crossrefs

Sequence in context: A251978 A258689 A258685 * A151818 A374368 A186604

Adjacent sequences: A031846 A031847 A031848 * A031850 A031851 A031852

Keyword

nonn

Author

David W. Wilson

Status

approved