A020369 Numbers k such that the continued fraction for sqrt(k) has period 30.

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

Links

Table of n, a(n) for n=1..43.

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

Adjacent sequences: A020366 A020367 A020368 * A020370 A020371 A020372

Keyword

nonn

Author

David W. Wilson

Status

approved