login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A020409 Numbers n such that continued fraction for sqrt(n) has period 70. 0
1366, 1579, 1684, 2707, 3189, 3371, 3446, 3826, 3851, 4132, 4612, 4869, 4881, 4948, 5169, 5464, 5563, 5867, 6313, 6721, 6772, 7366, 7478, 7876, 7907, 7918, 8006, 8122, 8152, 8198, 8449, 8564, 8754, 8950, 9053, 9188, 9538, 9787, 9814, 9923, 9994, 10198 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

cf70Q[n_]:=Module[{sr=Sqrt[n]}, !IntegerQ[sr]&&Length[ContinuedFraction[ sr][[2]]]==70]; Select[Range[11000], cf70Q] (* Harvey P. Dale, Jul 24 2012 *)

CROSSREFS

Sequence in context: A295466 A292780 A180089 * A231268 A192823 A221932

Adjacent sequences:  A020406 A020407 A020408 * A020410 A020411 A020412

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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 15 11:44 EDT 2021. Contains 345048 sequences. (Running on oeis4.)