%I #7 Aug 19 2014 09:01:33
%S 1999,2284,2461,2644,2671,2689,2956,2989,3061,3661,3697,3769,3817,
%T 4153,4201,4987,4989,5001,5101,5419,5469,5647,5812,5851,6067,6189,
%U 6281,6331,6581,6673,6689,6861,6883,7078,7141,7151,7261,7342,7354,7661,7693,7789
%N Period of continued fraction for sqrt(n) contains exactly 40 ones.
%t cf40Q[n_]:=Module[{s=Sqrt[n]},!IntegerQ[s]&&Count[ContinuedFraction[s][[2]],1]==40]; Select[Range[8000],cf40Q] (* _Harvey P. Dale_, Aug 19 2014 *)
%K nonn
%O 1,1
%A _David W. Wilson_
