A020349 Numbers k such that the continued fraction for sqrt(k) has period 10.

43, 67, 86, 93, 115, 116, 118, 129, 154, 159, 161, 162, 186, 237, 242, 243, 245, 246, 259, 286, 292, 297, 339, 344, 345, 354, 375, 403, 411, 451, 452, 453, 459, 464, 465, 469, 475, 490, 494, 497, 515, 516, 522, 532, 534, 536, 543, 563, 583, 591, 594, 595, 598, 603, 616

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• changed

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Harvey P. Dale)

Crossrefs

Contains A237604.

Programs

Mathematica

cf10Q[n_]:=Module[{sr=Sqrt[n]},!IntegerQ[sr]&&Length[ ContinuedFraction[ sr][[2]]]==10]; Select[Range[700],cf10Q] (* Harvey P. Dale, Mar 07 2012 *)