FOR THE NEGATIVE DETERMINANTS &C.
55
[496
496]
sses according to
rms (a, 3b, 3c, d)
when the terms
same thing when
lave no common
may be of the
; or it may be
O') considered
of the properly
cases, the cubic
)p, pp on /jl . ip,
inner case ; only
itive, the orders
composition ; viz.
form which by
simple form of
rms c, d, &c., of
symbol of com-
linant B'~ — A'C',
. 1 denotes that
’regular negative
s divisible by 3.
Table, but the
the number of
to the number
', %C 2 ), Det. DB\
rm corresponding
t in a letter of
i, [162], viz. that
for a pp form (A, B, C) of negative determinant, there is either no corresponding cubic
form, or else a single corresponding cubic form, according as (A, B, G) does not, or
does, produce by its triplication the principal form; but the particular theorem, in the
cases to which it applies, is the more convenient one: it shows at once that for a
regular negative determinant the number of cubic forms corresponding to a properly
primitive characteristic (or, what is the same thing, number of cubic classes of the
order (pp or ip) on pp) is 1 or 3, according as the number of quadratic classes is
not, or is, divisible by 3.
The inspection of the tables gives rise to other remarks, but at present I abstain
from pursuing the subject further; I will only notice that in some instances, for
example Det. — 224, the classes which correspond to characteristics of the principal
genus are partly of the order pp on pp and partly of the order ip on pp.
Table I. of the binary cubic forms, the determinants of which are the negative numbers
= 0 (mod. 4) from —4 to — 400.
Det. Order
4 x
Classes
ou
Charact.
Cornpn.
1
o,
-1,
o,
1
PP
pp
1,
0,
1
1
2
o,
- b
0,
2
PP
pp
1,
0,
2
1
3
o,
- b
0,
3
ip
pp
1,
0,
3
1
4
o,
-1,
0,
4
PP
pp
b
0,
4
1
1,
- b
-
1, 1
PP
2pp
2
(b
0, 1)
2. 1
5
0,
-1,
0,
5
PP
pp
1,
0,
5
1
6
0,
-1,
0,
6
ip
pp
b
0,
6
1
7
0,
-1,
0,
7
PP
pp
1,
0,
7
1
1,
0, -
2,
2 1
- PP
2 ip
2
(2,
± b 4)
2 or
1,
0, -
2,
— 2
1
8
0,
-1,
o,
8
PP
PP
1,
o,
8
1
0,
- 2
**9
o,
1
PP
2pp
2
(b
0, 2)
2.1
9
0,
-1,
0,
9
ip
PP
1,
o,
9
1
10
0,
- 1,
o,
10
PP
pp
b
0,
10
1
11
0,
-1,
o,
11 Ì
|
b
0,
11
1
0,
_ o
_
1, 1
\PP
PP
3,
b
4
a
0,
— 2
u 9
1,
1 J
1
3,
-
b 4
æ
12
0,
-1,
0,
12
ip
pp
1,
0,
12
l
13
0,
-1,
0,
13
PP
PP
b
0,
13
i
14
0,
- b
0,
14
PP
PP
1,
0,
14
l