A031859 Period of continued fraction for sqrt(n) contains exactly 91 ones.

64051, 75799, 76639, 85783, 129299, 132487, 146467, 148264, 151859, 162131, 162511, 192131, 214927, 223343, 224779, 224899, 250931, 251395, 262456, 273607, 289931, 292811, 316611, 318491, 331255, 343864, 345043, 346019, 347459, 353995

Offset

1,1

Links

Table of n, a(n) for n=1..30.

Mathematica

cf91Q[n_]:=Module[{sr=Sqrt[n], p}, p=If[IntegerQ[sr], 1, Count[ ContinuedFraction[ sr][[2]], 1]]; p==91]; Select[Range[400000], cf91Q] (* Harvey P. Dale, Jan 22 2014 *)

Crossrefs

Sequence in context: A250823 A054738 A250617 * A182811 A236702 A224827

Adjacent sequences: A031856 A031857 A031858 * A031860 A031861 A031862

Keyword

nonn

Author

David W. Wilson

Status

approved