%I #14 Jul 11 2021 01:27:35
%S 1381,1789,2521,3754,3994,5953,6389,7349,7765,7801,8297,8842,9274,
%T 10253,12413,14458,15349,15749,16073,16229,19073,21485,22433,24106,
%U 24317,24506,24538,24929,25577,25706,26170,26773,26954,28018,28345,30197,32218,32290
%N Numbers k such that the continued fraction for sqrt(k) has period 67.
%t cf67Q[n_]:=Module[{s=Sqrt[n]},If[IntegerQ[s],1,Length[ ContinuedFraction[ s][[2]]]]==67]; Select[Range[33000],cf67Q] (* _Harvey P. Dale_, Sep 21 2018 *)
%Y Cf. A003285.
%K nonn
%O 1,1
%A _David W. Wilson_