A031698 Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 20.

101, 402, 903, 1604, 2505, 3606, 4907, 6408, 8109, 10010, 12111, 14412, 16913, 19614, 22515, 25616, 28917, 32418, 36119, 40020, 44121, 48422, 48862, 52923, 57624, 62525, 67626, 72927, 78428, 84129, 90030, 96131, 102432, 108933, 115634, 122535, 129636

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Links

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

Crossrefs

Different from A055438.

Programs

Mathematica

Select[Range[200000],!IntegerQ[Sqrt[#]]&&Min[ContinuedFraction[Sqrt[#]][[2]]]==20&] (* Vincenzo Librandi, Feb 06 2012 *)