OFFSET
1,1
MATHEMATICA
cf86Q[n_]:=Module[{s=Sqrt[n], cf, len}, cf=If[IntegerQ[s], {1}, ContinuedFraction[ s][[2]]]; len=Length[cf]; EvenQ[len]&&cf[[len/2]] == 86]; Select[ Range[17000], cf86Q] (* Harvey P. Dale, Jan 15 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved