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A031783
Period of continued fraction for sqrt(n) contains exactly 15 ones.
0
871, 2675, 3683, 4819, 5863, 6731, 8056, 8827, 9592, 9971, 10207, 10323, 12019, 12455, 12584, 15224, 15563, 15696, 16168, 16536, 16808, 17155, 17235, 18535, 19039, 20923, 20995, 21255, 21576, 22608, 24464, 24495, 24883, 26151, 26207, 26827, 26967
OFFSET
1,1
MATHEMATICA
cf15Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Count[ContinuedFraction[ s] [[2]], 1]]==15]; Select[Range[27000], cf15Q] (* Harvey P. Dale, May 09 2021 *)
CROSSREFS
Sequence in context: A205426 A035855 A317806 * A253167 A214285 A251841
KEYWORD
nonn
STATUS
approved