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A031654 Numbers n such that continued fraction for sqrt(n) has odd period and central term 66. 0
1090, 10009, 27581, 89482, 90682, 134077, 135545, 185069, 186793, 246241, 316133, 321778, 487645, 581173, 582698, 585754, 590353, 593429, 682901, 686209, 687866, 691186, 696181, 699521, 796393, 814333, 930137, 937865, 941741, 1049537, 1061861 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

op66Q[n_]:=Module[{s=Sqrt[n], cf, len}, cf=If[IntegerQ[s], {1, 1}, ContinuedFraction[ s][[2]]]; len=Length[cf]; OddQ[len]&&cf[[(len+1)/2]] == 66]; Select[Range[11*10^5], op66Q] (* Harvey P. Dale, Mar 14 2016 *)

CROSSREFS

Sequence in context: A023101 A169977 A031744 * A031531 A161118 A031711

Adjacent sequences:  A031651 A031652 A031653 * A031655 A031656 A031657

KEYWORD

nonn

AUTHOR

David W. Wilson

EXTENSIONS

Terms corrected and definition corrected by Harvey P. Dale, Mar 14 2016

STATUS

approved

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Last modified February 19 10:03 EST 2020. Contains 332041 sequences. (Running on oeis4.)