OFFSET
1,1
MATHEMATICA
cf68Q[n_]:=Module[{s=Sqrt[n], cf, len}, cf=If[IntegerQ[s], {1}, ContinuedFraction[ s][[2]]]; len=Length[cf]; EvenQ[len]&&cf[[len/2]]==68]; Select[Range[11000], cf68Q] (* Harvey P. Dale, Jan 10 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved