OFFSET
1,1
LINKS
T. D. Noe, Table of n, a(n) for n = 1..1000
MATHEMATICA
n = 1; t = {}; While[Length[t] < 50, n++; If[! IntegerQ[Sqrt[n]], c = ContinuedFraction[Sqrt[n]]; len = Length[c[[2]]]; If[EvenQ[len] && c[[2, len/2]] == 3, AppendTo[t, n]]]]; t (* T. D. Noe, Apr 04 2014 *)
cf3Q[n_]:=Module[{s=Sqrt[n], cf, len}, cf=If[IntegerQ[s], {1}, ContinuedFraction[ s][[2]]]; len=Length[cf]; EvenQ[len]&&cf[[len/2]] == 3]; Select[Range[1600], cf3Q] (* Harvey P. Dale, Aug 15 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved