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A020417 Numbers k such that the continued fraction for sqrt(k) has period 78. 0
1894, 2539, 3241, 3862, 4417, 4691, 4989, 5158, 5251, 5366, 5489, 5977, 6139, 6393, 6514, 6628, 7081, 7286, 7414, 7576, 7941, 8699, 8913, 9019, 9186, 9329, 9491, 9547, 9764, 10105, 10157, 10351, 10436, 10456, 10821, 10916, 11012, 11153, 11469, 11586 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..40.

MATHEMATICA

cf78Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Length[ ContinuedFraction[ s][[2]]]]==78]; Select[Range[12000], cf78Q] (* Harvey P. Dale, Jan 16 2022 *)

CROSSREFS

Sequence in context: A254285 A035869 A045198 * A218848 A219427 A297320

Adjacent sequences:  A020414 A020415 A020416 * A020418 A020419 A020420

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified May 27 14:37 EDT 2022. Contains 354105 sequences. (Running on oeis4.)