login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A020407 Numbers k such that the continued fraction for sqrt(k) has period 68. 0
1879, 1951, 2239, 3079, 3244, 3991, 4231, 4567, 4689, 4871, 5361, 5553, 5937, 5998, 6044, 6064, 6295, 6304, 6346, 6535, 6719, 6906, 7276, 7564, 7615, 7629, 8423, 8444, 8748, 8764, 8894, 8896, 8959, 9007, 9117, 9223, 9276, 9358, 9564, 9741, 9784, 10078 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

cf68Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Length[ ContinuedFraction[ s][[2]]]]==68]; Select[Range[11000], cf68Q] (* Harvey P. Dale, Aug 20 2015 *)

CROSSREFS

Cf. A003285.

Sequence in context: A127410 A237570 A045201 * A320719 A235193 A072494

Adjacent sequences:  A020404 A020405 A020406 * A020408 A020409 A020410

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 27 07:25 EDT 2022. Contains 354093 sequences. (Running on oeis4.)