A031728 Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 50.

626, 2502, 5628, 10004, 15630, 22506, 30632, 40008, 50634, 62510, 75636, 90012, 105638, 122514, 140640, 160016, 180642, 202518, 225644, 250020, 275646, 302522, 330648, 360024, 390650, 422526, 455652, 490028, 525654, 562530, 600656, 640032

Offset

1,1

Comments

a(n) = 625n^2 + n for n < 53, but a(53) = 1692652. - Charles R Greathouse IV, Aug 04 2017

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Mathematica

lt50Q[n_]:=Module[{s=Sqrt[n]}, !IntegerQ[s]&&Min[ContinuedFraction[s][[2]]]==50]; Select[Range[641000], lt50Q] (* Harvey P. Dale, Mar 05 2013 *)

Crossrefs

Sequence in context: A345513 A345766 A158383 * A031638 A098262 A031523

Adjacent sequences: A031725 A031726 A031727 * A031729 A031730 A031731

Keyword

nonn

Author

David W. Wilson

Status

approved