A031810 Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 42 ones.

1516, 2164, 2374, 2881, 3049, 3259, 3313, 3319, 3511, 3571, 3631, 3868, 4054, 4099, 4449, 4549, 5116, 5121, 5158, 5221, 5227, 5422, 5446, 5596, 6043, 6073, 6163, 6374, 6577, 6609, 6836, 6859, 7401, 7417, 7841, 7867, 8219, 8293, 8413, 8452, 8486, 8527

Offset

1,1

Links

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

Mathematica

q[k_] := Module[{c = ContinuedFraction[Sqrt[k]]}, Length[c] == 2 && Count[c[[2]], 1] == 42]; Select[Range[9000], q] (* Amiram Eldar, Aug 11 2025 *)

Crossrefs

Sequence in context: A064584 A318713 A252508 * A020415 A257753 A236724

Adjacent sequences: A031807 A031808 A031809 * A031811 A031812 A031813

Keyword

nonn

Author

David W. Wilson

Status

approved