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A020352
Numbers k such that the continued fraction for sqrt(k) has period 13.
0
193, 281, 481, 565, 593, 746, 778, 997, 1082, 1138, 1250, 1514, 1930, 2042, 2426, 2477, 2837, 2930, 3121, 3145, 3338, 3413, 3625, 3797, 3853, 3925, 4001, 4058, 4421, 4745, 5122, 5234, 5741, 6010, 6170, 6481, 7025, 7250, 7418, 7730, 7757, 7877, 7930, 8450
OFFSET
1,1
MATHEMATICA
cf13Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Length[ContinuedFraction[s][[2]]]==13]]; Select[ Range[9000], cf13Q] (* Harvey P. Dale, Aug 07 2023 *)
CROSSREFS
Sequence in context: A226147 A142925 A060333 * A146338 A201858 A146360
KEYWORD
nonn
STATUS
approved