A020393 Numbers k such that the continued fraction for sqrt(k) has period 54.

886, 1747, 1821, 2361, 2404, 2662, 2899, 2998, 3097, 3307, 3412, 3796, 3907, 4061, 4166, 4246, 4377, 4459, 4724, 4769, 4819, 4866, 4911, 5044, 5079, 5147, 5171, 5299, 5531, 5561, 5574, 5599, 5665, 5860, 5889, 5987, 6011, 6059, 6190, 6262, 6265, 6323

Offset

1,1

Links

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

Mathematica

cf54Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Length[ ContinuedFraction[ s][[2]]]]==54]; Select[Range[6400], cf54Q] (* Harvey P. Dale, Mar 24 2017 *)

Crossrefs

Cf. A003285.

Sequence in context: A295443 A261760 A031794 * A103811 A190354 A164513

Adjacent sequences: A020390 A020391 A020392 * A020394 A020395 A020396

Keyword

nonn

Author

David W. Wilson

Status

approved