login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A240950 Numbers n with the property that the continued fraction for sqrt(n) has odd period length, omitting those values of n of the form m^2+1. 1
13, 29, 41, 53, 58, 61, 73, 74, 85, 89, 97, 106, 109, 113, 125, 130, 137, 149, 157, 173, 181, 185, 193, 202, 218, 229, 233, 241, 250, 265, 269, 274, 277, 281, 293, 298, 313, 314, 317, 337, 338, 346, 349, 353, 365, 370, 373, 389, 394, 397, 409, 421, 425, 433 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

p^2-n*q^2=-1 is solvable for integers p and q.

A031396 is the union of this sequence with A002522.

LINKS

Colin Barker, Table of n, a(n) for n = 1..1000

EXAMPLE

sqrt(13)= [3;1,1,1,1,6].

sqrt(29)= [5;2,1,1,2,10].

CROSSREFS

Cf. A002522, A003814, A031396.

Sequence in context: A141555 A036974 A045472 * A141293 A120827 A228069

Adjacent sequences:  A240947 A240948 A240949 * A240951 A240952 A240953

KEYWORD

nonn

AUTHOR

Takao Ito, Aug 04 2014

EXTENSIONS

More terms from Colin Barker, Dec 18 2014

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified January 20 17:47 EST 2018. Contains 297961 sequences.