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.

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

Links

Table of n, a(n) for n=1..31.

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

Adjacent sequences: A031614 A031615 A031616 * A031618 A031619 A031620

Keyword

nonn

Author

David W. Wilson

Extensions

Corrected by Harvey P. Dale, Dec 14 2011

Status

approved