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A020369
Numbers k such that the continued fraction for sqrt(k) has period 30.
0
379, 436, 649, 772, 849, 946, 981, 1094, 1123, 1234, 1309, 1317, 1413, 1497, 1574, 1626, 1675, 1729, 1793, 1844, 1867, 1942, 2003, 2036, 2158, 2171, 2187, 2214, 2217, 2245, 2260, 2265, 2319, 2353, 2456, 2485, 2487, 2491, 2512, 2513, 2563, 2582, 2623
OFFSET
1,1
MATHEMATICA
cf30Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Length[ ContinuedFraction[ s][[2]]]]==30]; Select[Range[3000], cf30Q] (* Harvey P. Dale, May 11 2021 *)
CROSSREFS
Sequence in context: A228554 A108385 A341188 * A142207 A058995 A161612
KEYWORD
nonn
STATUS
approved