A031689 Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 11.

123, 488, 1095, 1944, 3035, 4368, 5943, 7760, 9819, 12120, 14663, 16152, 17448, 19344, 20475, 23744, 27255, 31008, 35003, 37284, 39240, 43719, 48440, 53403, 53866, 58608, 59093, 64055, 64562, 67128, 69744, 75675, 81848, 88263, 94920, 101819

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Links

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

Crossrefs

Cf. A031424.

Programs

Mathematica

Select[Range[110000],!IntegerQ[Sqrt[#]]&&Min[ContinuedFraction[Sqrt[#]][[2]]]==11&] (* Vincenzo Librandi, Jan 27 2012 *)

Extensions

Content that was based on the incorrect assumption that a(n)=121*n^2+2*n removed by R. J. Mathar, Nov 18 2010