A020400 Numbers k such that the continued fraction for sqrt(k) has period 61.

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

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

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