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A031849
Period of continued fraction for sqrt(n) contains exactly 81 ones.
0
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
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
KEYWORD
nonn
STATUS
approved