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A013649 Period of continued fraction for sqrt(n) contains exactly two 1's. 1
14, 19, 22, 23, 29, 33, 34, 45, 47, 52, 53, 54, 59, 60, 62, 69, 70, 71, 77, 78, 79, 85, 95, 96, 98, 107, 114, 117, 118, 119, 125, 127, 138, 140, 141, 142, 149, 153, 154, 164, 165, 167, 173, 178, 187, 188, 189, 192, 194, 202, 205, 206, 216, 218, 219, 220, 221, 222, 223, 229 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

Kenneth H. Rosen, Elementary Number Theory and Its Applications, Addison-Wesley, 1984, page 426 (but beware of errors!).

LINKS

Robert Israel, Table of n, a(n) for n = 1..8300

MAPLE

filter:= n -> not issqr(n) and numboccur(1, numtheory:-cfrac(sqrt(n), periodic, quotients)[2])=2:

select(filter, [$1..500]); # Robert Israel, Nov 01 2018

MATHEMATICA

Select[ Range@ 1900, !IntegerQ[ Sqrt@ #] && Count[ ContinuedFraction[ Sqrt@ #][[2]], 1] == 2 &] (* Robert G. Wilson v, Jul 03 2011 *)

CROSSREFS

Sequence in context: A165228 A205866 A248134 * A013657 A013653 A072124

Adjacent sequences:  A013646 A013647 A013648 * A013650 A013651 A013652

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified February 22 19:59 EST 2019. Contains 320403 sequences. (Running on oeis4.)