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A031617
Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 29.
0
5501, 10453, 17770, 18037, 26365, 27017, 36269, 49066, 63793, 76537, 81017, 112754, 114773, 116129, 132394, 133121, 134581, 135314, 136049, 136786, 138266, 139009, 139754, 140501, 154393, 159133, 180617, 185741, 187465, 203461, 204362
OFFSET
1,1
MATHEMATICA
opct29Q[n_]:=Module[{cf=ContinuedFraction[Sqrt[n]][[2]], len}, len= Length[ cf]; OddQ[len]&&cf[[Floor[len/2]]]==29]; Select[Range[205000], !IntegerQ[Sqrt[#]]&&opct29Q[#]&] (* Harvey P. Dale, Dec 14 2011 *)
CROSSREFS
Subsequence of A003814.
Sequence in context: A251877 A252312 A247924 * A045132 A096702 A252621
KEYWORD
nonn
EXTENSIONS
Corrected by Harvey P. Dale, Dec 14 2011
STATUS
approved