megrez number field tables repackaged

[Karim Belabas <Karim.Belabas@math.u-bordeaux1.fr>]

Dear PARI lovers,

  I have repackaged the number field tables published by the Bordeaux
computational number theory group (H. Cohen and his team) around 1995.

  http://pari.math.u-bordeaux1.fr/pub/pari/packages/nftables.tgz

The original tables are kept for reference at the same address
ftp://megrez.math.u-bordeaux.fr/pub/numberfields/ as before
(Judging from some index files, old data files corresponding to most
quadratic fields have apparently disappeared, and I couldnt't trace
them yet. So the data was generated anew.)

Compared to the original tables, the new version uses a single
(human-readable) file for a given signature, and stores only 

* the field equation [ from which a bnf can be recomputed ],

* the field discriminant & class number, as well as the class group
decomposition as a product of cyclic groups (bnf.cyc) [ for quick filtering ].

N.B: Computing bnfinit & polgalois for all fields in the table takes
less than 2 hours in current PARI/GP, so there was no need to include that
in the tables. As a result, these are considerably smaller (1/10th the size)

More details in the README:

  http://pari.math.u-bordeaux1.fr/pub/pari/packages/nftables/README

Please report any problem !

Have fun,

    K.B.

P.S: A few wrong cyclic structures & class numbers (12 fields) have been
corrected.

--
Karim Belabas, IMB (UMR 5251)  Tel: (+33) (0)5 40 00 26 17
Universite Bordeaux 1          Fax: (+33) (0)5 40 00 69 50
351, cours de la Liberation    http://www.math.u-bordeaux.fr/~belabas/
F-33405 Talence (France)       http://pari.math.u-bordeaux.fr/  [PARI/GP]
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