A031806 Period of continued fraction for sqrt(n) contains exactly 38 ones.

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

Links

Table of n, a(n) for n=1..42.

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 A258965 A250009

Adjacent sequences: A031803 A031804 A031805 * A031807 A031808 A031809

Keyword

nonn

Author

David W. Wilson

Status

approved