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A031819
Period of continued fraction for sqrt(n) contains exactly 51 ones.
0
13939, 28531, 40891, 50059, 52264, 55183, 58927, 65656, 66887, 73051, 82519, 94824, 108539, 111896, 113263, 114955, 119743, 131723, 131811, 133867, 147823, 155803, 158299, 161155, 162819, 163283, 169336, 169663, 169675, 176623, 180671, 187039
OFFSET
1,1
MATHEMATICA
cf51Q[n_]:=Module[{sr=Sqrt[n], x}, x=If[IntegerQ[sr], 1, Count[ ContinuedFraction[ sr][[2]], 1]]; x==51]; Select[Range[200000], cf51Q] (* Harvey P. Dale, Jan 19 2014 *)
CROSSREFS
Sequence in context: A244273 A118464 A031666 * A066939 A215150 A215944
KEYWORD
nonn
STATUS
approved