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A020409
Numbers k such that the continued fraction for sqrt(k) has period 70.
0
1366, 1579, 1684, 2707, 3189, 3371, 3446, 3826, 3851, 4132, 4612, 4869, 4881, 4948, 5169, 5464, 5563, 5867, 6313, 6721, 6772, 7366, 7478, 7876, 7907, 7918, 8006, 8122, 8152, 8198, 8449, 8564, 8754, 8950, 9053, 9188, 9538, 9787, 9814, 9923, 9994, 10198
OFFSET
1,1
MATHEMATICA
cf70Q[n_]:=Module[{sr=Sqrt[n]}, !IntegerQ[sr]&&Length[ContinuedFraction[ sr][[2]]]==70]; Select[Range[11000], cf70Q] (* Harvey P. Dale, Jul 24 2012 *)
CROSSREFS
Cf. A003285.
Sequence in context: A295466 A292780 A180089 * A231268 A192823 A221932
KEYWORD
nonn
STATUS
approved