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A020387 Numbers k such that the continued fraction for sqrt(k) has period 48. 0
631, 844, 1006, 1341, 1441, 1663, 1689, 1783, 1822, 1837, 1871, 2062, 2287, 2413, 2479, 2517, 2572, 2591, 2846, 2853, 3103, 3184, 3273, 3309, 3340, 3376, 3448, 3521, 3537, 3767, 4109, 4361, 4497, 4526, 4585, 4750, 4766, 4833, 4849, 4921, 4986, 5118 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..42.

MATHEMATICA

cf48Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 0, Length[ ContinuedFraction[ s][[2]]]]==48]; Select[Range[5200], cf48Q] (* Harvey P. Dale, Nov 04 2020 *)

CROSSREFS

Cf. A003285.

Sequence in context: A045168 A270802 A119504 * A217494 A105305 A252412

Adjacent sequences:  A020384 A020385 A020386 * A020388 A020389 A020390

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified October 27 23:46 EDT 2021. Contains 348305 sequences. (Running on oeis4.)