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A020411 Numbers k such that the continued fraction for sqrt(k) has period 72. 0
2476, 2569, 2661, 2949, 3669, 3727, 3847, 4078, 4101, 4533, 4581, 5146, 5191, 5399, 5591, 5671, 6079, 6297, 6476, 6509, 6777, 6811, 6904, 6931, 7111, 7189, 7264, 7454, 7583, 7781, 8143, 8213, 8231, 8263, 8284, 8659, 8921, 9175, 9313, 9354, 9655, 9692 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

upto=10000; Select[Complement[Range[upto], Range[Floor[Sqrt[upto]]]^2], Length[ContinuedFraction[Sqrt[#]][[2]]]==72&] (* Harvey P. Dale, Jul 04 2011 *)

CROSSREFS

Cf. A003285.

Sequence in context: A282559 A278733 A236785 * A124594 A241048 A291199

Adjacent sequences:  A020408 A020409 A020410 * A020412 A020413 A020414

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified May 16 15:15 EDT 2022. Contains 353706 sequences. (Running on oeis4.)