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A031806
Period of continued fraction for sqrt(n) contains exactly 38 ones.
0
2038, 2149, 2179, 2389, 2791, 2974, 3193, 3921, 3943, 4027, 4101, 4126, 4237, 4417, 4601, 4691, 4701, 4801, 4969, 5023, 5209, 5279, 5737, 5836, 5926, 5961, 6029, 6046, 6346, 6393, 6429, 6449, 6491, 6521, 6526, 6547, 6718, 6733, 6799, 6811, 6826, 6847
OFFSET
1,1
MATHEMATICA
cf38Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Count[ ContinuedFraction[ s][[2]], 1]]==38]; Select[Range[7000], cf38Q] (* Harvey P. Dale, Feb 12 2016 *)
CROSSREFS
Sequence in context: A098808 A212477 A020413 * A186045 A377928 A258965
KEYWORD
nonn
STATUS
approved