A020417 Numbers k such that the continued fraction for sqrt(k) has period 78.

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

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