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Properties

Label 21T5
Degree $21$
Order $42$
Cyclic no
Abelian no
Solvable yes
Primitive no
$p$-group no
Group: $D_{21}$

Related objects

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Group action invariants

Degree $n$:  $21$
Transitive number $t$:  $5$
Group:  $D_{21}$
Parity:  $1$
Primitive:  no
Nilpotency class:  $-1$ (not nilpotent)
$|\Aut(F/K)|$:  $1$
Generators:  (1,8)(2,7)(3,9)(4,6)(10,19)(11,21)(12,20)(13,17)(14,16)(15,18), (1,17)(2,16)(3,18)(4,14)(5,13)(6,15)(7,11)(8,10)(9,12)(19,20)

Low degree resolvents

|G/N|Galois groups for stem field(s)
$2$:  $C_2$
$6$:  $S_3$
$14$:  $D_{7}$

Resolvents shown for degrees $\leq 47$

Subfields

Degree 3: $S_3$

Degree 7: $D_{7}$

Low degree siblings

42T5

Siblings are shown with degree $\leq 47$

A number field with this Galois group has no arithmetically equivalent fields.

Conjugacy classes

Cycle TypeSizeOrderRepresentative
$ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 $ $1$ $1$ $()$
$ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1 $ $21$ $2$ $( 2, 3)( 4,21)( 5,20)( 6,19)( 7,16)( 8,18)( 9,17)(10,13)(11,15)(12,14)$
$ 3, 3, 3, 3, 3, 3, 3 $ $2$ $3$ $( 1, 2, 3)( 4, 5, 6)( 7, 8, 9)(10,11,12)(13,14,15)(16,17,18)(19,20,21)$
$ 7, 7, 7 $ $2$ $7$ $( 1, 4, 9,12,14,17,21)( 2, 5, 7,10,15,18,19)( 3, 6, 8,11,13,16,20)$
$ 21 $ $2$ $21$ $( 1, 5, 8,12,15,16,21, 2, 6, 9,10,13,17,19, 3, 4, 7,11,14,18,20)$
$ 21 $ $2$ $21$ $( 1, 6, 7,12,13,18,21, 3, 5, 9,11,15,17,20, 2, 4, 8,10,14,16,19)$
$ 21 $ $2$ $21$ $( 1, 7,13,21, 5,11,17, 2, 8,14,19, 6,12,18, 3, 9,15,20, 4,10,16)$
$ 21 $ $2$ $21$ $( 1, 8,15,21, 6,10,17, 3, 7,14,20, 5,12,16, 2, 9,13,19, 4,11,18)$
$ 7, 7, 7 $ $2$ $7$ $( 1, 9,14,21, 4,12,17)( 2, 7,15,19, 5,10,18)( 3, 8,13,20, 6,11,16)$
$ 21 $ $2$ $21$ $( 1,10,20, 9,18, 6,14, 2,11,21, 7,16, 4,15, 3,12,19, 8,17, 5,13)$
$ 21 $ $2$ $21$ $( 1,11,19, 9,16, 5,14, 3,10,21, 8,18, 4,13, 2,12,20, 7,17, 6,15)$
$ 7, 7, 7 $ $2$ $7$ $( 1,12,21, 9,17, 4,14)( 2,10,19, 7,18, 5,15)( 3,11,20, 8,16, 6,13)$

Group invariants

Order:  $42=2 \cdot 3 \cdot 7$
Cyclic:  no
Abelian:  no
Solvable:  yes
GAP id:  [42, 5]
Character table:    
      2  1  1  .  .   .   .   .   .  .   .   .  .
      3  1  .  1  1   1   1   1   1  1   1   1  1
      7  1  .  1  1   1   1   1   1  1   1   1  1

        1a 2a 3a 7a 21a 21b 21c 21d 7b 21e 21f 7c
     2P 1a 1a 3a 7b 21d 21c 21e 21f 7c 21a 21b 7a
     3P 1a 2a 1a 7c  7c  7c  7a  7a 7a  7b  7b 7b
     5P 1a 2a 3a 7b 21c 21d 21f 21e 7c 21b 21a 7a
     7P 1a 2a 3a 1a  3a  3a  3a  3a 1a  3a  3a 1a
    11P 1a 2a 3a 7c 21e 21f 21b 21a 7a 21c 21d 7b
    13P 1a 2a 3a 7a 21b 21a 21d 21c 7b 21f 21e 7c
    17P 1a 2a 3a 7c 21f 21e 21a 21b 7a 21d 21c 7b
    19P 1a 2a 3a 7b 21d 21c 21e 21f 7c 21a 21b 7a

X.1      1  1  1  1   1   1   1   1  1   1   1  1
X.2      1 -1  1  1   1   1   1   1  1   1   1  1
X.3      2  . -1  2  -1  -1  -1  -1  2  -1  -1  2
X.4      2  .  2  A   A   A   C   C  C   B   B  B
X.5      2  .  2  B   B   B   A   A  A   C   C  C
X.6      2  .  2  C   C   C   B   B  B   A   A  A
X.7      2  . -1  C   D   E   I   H  B   F   G  A
X.8      2  . -1  C   E   D   H   I  B   G   F  A
X.9      2  . -1  A   F   G   E   D  C   I   H  B
X.10     2  . -1  A   G   F   D   E  C   H   I  B
X.11     2  . -1  B   H   I   F   G  A   D   E  C
X.12     2  . -1  B   I   H   G   F  A   E   D  C

A = E(7)^2+E(7)^5
B = E(7)+E(7)^6
C = E(7)^3+E(7)^4
D = E(21)^5+E(21)^16
E = E(21)^2+E(21)^19
F = E(21)^8+E(21)^13
G = E(21)+E(21)^20
H = E(21)^10+E(21)^11
I = E(21)^4+E(21)^17