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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A143746 The number of totally real number fields of degree n with definite Eichler orders <=2. 2
1, 39, 47, 108, 37, 40, 4, 3 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

By the Odlyzko bounds, there are only finitely many such fields and they have been explicitly enumerated (by Voight) and no field satisfying the bound with n => 9, for a total of 279 fields. Kirschmer and Voight (pp. 26-27) also enumerate the ideal classes explicitly, Abstract: We provide algorithms to count and enumerate representatives of the (right) ideal classes of an Eichler order in a quaternion algebra defined over a number field. We analyze the run time of these algorithms and consider several related problems, including the computation of two-sided ideal classes, isomorphism classes of orders, connecting ideals for orders and ideal principalization. We conclude by giving the complete list of definite Eichler orders with class number at most 2.

LINKS

Markus Kirschmer and John Voight, Algorithmic enumeration of ideal classes for quaternion orders, arXiv:0808.3833 [math.NT]

John Voight, Enumeration of totally real number fields of bounded root discriminant, Algorithmic number theory, eds. Alfred van der Poorten and Andreas Stein, Lecture notes in computer science, vol. 5011, Springer, Berlin, 2008, 268-281.

CROSSREFS

Sequence in context: A061756 A119028 A046512 * A064399 A050439 A199993

Adjacent sequences:  A143743 A143744 A143745 * A143747 A143748 A143749

KEYWORD

nonn,fini,full

AUTHOR

Jonathan Vos Post (jvospost3(AT)gmail.com), Aug 30 2008

EXTENSIONS

Replaced link to cached arXiv by link to permanent URL - R. J. Mathar (mathar(AT)strw.leidenuniv.nl-), Mar 01 2010

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 04:21 EST 2012. Contains 205978 sequences.