A031796 - OEIS

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A031796

Period of continued fraction for sqrt(n) contains exactly 28 ones.

1381, 1501, 1588, 1609, 2137, 2293, 2469, 2473, 2476, 2481, 2497, 2529, 2564, 2721, 2909, 3013, 3073, 3076, 3117, 3119, 3149, 3241, 3307, 3326, 3343, 3539, 3583, 3748, 3847, 3884, 3994, 4039, 4078, 4117, 4269, 4349, 4456, 4459, 4492, 4581, 4612, 4654

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..42.

MATHEMATICA

cf28Q[n_]:=With[{s=Sqrt[n]}, If[IntegerQ[s], 1, Count[ContinuedFraction[s][[2]], 1]]==28]; Select[ Range[ 5000], cf28Q] (* Harvey P. Dale, Aug 02 2024 *)

CROSSREFS

Sequence in context: A209791 A051114 A139667 * A020406 A277632 A241483

Adjacent sequences: A031793 A031794 A031795 * A031797 A031798 A031799

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved