A020384 Numbers k such that the continued fraction for sqrt(k) has period 45.

1249, 1321, 1753, 2113, 2549, 2729, 2833, 3085, 3557, 3581, 3833, 4285, 4673, 4885, 5065, 5389, 5573, 6257, 6317, 6977, 8093, 8753, 8765, 9257, 9914, 10433, 10690, 11002, 11597, 12233, 12965, 13477, 13985, 14033, 14065, 14578, 14681, 14837, 15013

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 && Length[c[[2]]] == 45]; Select[Range[16000], q] (* Amiram Eldar, Aug 23 2025 *)

Crossrefs

Cf. A003285.

Sequence in context: A233201 A233244 A233222 * A377564 A376502 A086709

Adjacent sequences: A020381 A020382 A020383 * A020385 A020386 A020387

Keyword

nonn

Author

David W. Wilson

Status

approved