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A020400 Numbers k such that the continued fraction for sqrt(k) has period 61. 0
2053, 2909, 4177, 6197, 7594, 9385, 9865, 9985, 10825, 10954, 11306, 11425, 11657, 12266, 12713, 13234, 14381, 14386, 14489, 14753, 14765, 15034, 15329, 15497, 16241, 16369, 16937, 17642, 18610, 19013, 19562, 19930, 20098, 20245, 21970, 22189, 24250 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..37.

MATHEMATICA

cf61Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Length[ ContinuedFraction[ s][[2]]]]==61]; Select[Range[25000], cf61Q] (* Harvey P. Dale, Aug 07 2021 *)

CROSSREFS

Cf. A003285.

Sequence in context: A168190 A238934 A084550 * A068723 A252187 A252509

Adjacent sequences:  A020397 A020398 A020399 * A020401 A020402 A020403

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified May 27 22:39 EDT 2022. Contains 354110 sequences. (Running on oeis4.)