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A020388 Numbers k such that the continued fraction for sqrt(k) has period 49. 0
1021, 1597, 2617, 2746, 2861, 3041, 3881, 4049, 6469, 6737, 8497, 9677, 9970, 10049, 10181, 11114, 12829, 12973, 14426, 14842, 15145, 16141, 16277, 18265, 19357, 19385, 20605, 21002, 22738, 24842, 26002, 26489, 26938, 27733, 28922, 29362, 29789, 30025 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..38.

MATHEMATICA

cf49Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Length[ ContinuedFraction[ s] [[2]]]]==49]; Select[Range[31000], cf49Q] (* Harvey P. Dale, Mar 31 2018 *)

CROSSREFS

Sequence in context: A179033 A082059 A081633 * A306596 A287639 A261676

Adjacent sequences:  A020385 A020386 A020387 * A020389 A020390 A020391

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified October 27 04:30 EDT 2021. Contains 348270 sequences. (Running on oeis4.)