%I #12 Jul 11 2021 07:25:00
%S 457,881,1049,1181,1189,1306,1585,1594,1754,2125,2797,2906,4121,4157,
%T 4234,4253,4330,4442,4469,4517,4913,5077,5597,6418,7442,8249,8345,
%U 8570,8689,8825,9593,10145,10301,10498,10625,10673,10889,11401,11930,12053
%N Numbers k such that the continued fraction for sqrt(k) has period 25.
%t cf25Q[n_]:=Module[{s=Sqrt[n]},If[IntegerQ[s],1,Length[ ContinuedFraction[ s][[2]]]]==25]; Select[Range[13000],cf25Q] (* _Harvey P. Dale_, May 05 2020 *)
%K nonn
%O 1,1
%A _David W. Wilson_
