Properties

Label 21T33
Degree $21$
Order $2520$
Cyclic no
Abelian no
Solvable no
Primitive yes
$p$-group no
Group: $A_7$

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Show commands: Magma

magma: G := TransitiveGroup(21, 33);
 

Group invariants

Abstract group:  $A_7$
magma: IdentifyGroup(G);
 
Order:  $2520=2^{3} \cdot 3^{2} \cdot 5 \cdot 7$
magma: Order(G);
 
Cyclic:  no
magma: IsCyclic(G);
 
Abelian:  no
magma: IsAbelian(G);
 
Solvable:  no
magma: IsSolvable(G);
 
Nilpotency class:   not nilpotent
magma: NilpotencyClass(G);
 

Group action invariants

Degree $n$:  $21$
magma: t, n := TransitiveGroupIdentification(G); n;
 
Transitive number $t$:  $33$
magma: t, n := TransitiveGroupIdentification(G); t;
 
Parity:  $1$
magma: IsEven(G);
 
Primitive:  yes
magma: IsPrimitive(G);
 
$\card{\Aut(F/K)}$:  $1$
magma: Order(Centralizer(SymmetricGroup(n), G));
 
Generators:  $(1,7,12,16,19,21,6)(2,8,13,17,20,5,11)(3,9,14,18,4,10,15)$, $(4,6,5)(9,11,10)(13,15,14)(16,18,17)(19,20,21)$
magma: Generators(G);
 

Low degree resolvents

none

Resolvents shown for degrees $\leq 47$

Subfields

Degree 3: None

Degree 7: None

Low degree siblings

7T6, 15T47 x 2, 35T28, 42T294, 42T299

Siblings are shown with degree $\leq 47$

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

Conjugacy classes

LabelCycle TypeSizeOrderIndexRepresentative
1A $1^{21}$ $1$ $1$ $0$ $()$
2A $2^{8},1^{5}$ $105$ $2$ $8$ $( 1, 2)( 4, 5)( 8,12)( 9,14)(10,13)(11,15)(16,17)(20,21)$
3A $3^{5},1^{6}$ $70$ $3$ $10$ $( 1, 4, 2)( 7, 9,13)( 8,16,12)(10,19,14)(11,20,15)$
3B $3^{7}$ $280$ $3$ $14$ $( 1,11, 9)( 2,21,16)( 3,15,19)( 4, 6,20)( 5,18,13)( 7,10, 8)(12,14,17)$
4A $4^{4},2^{2},1$ $630$ $4$ $14$ $( 1, 4, 2, 5)( 3, 6)( 7,19)( 8,20,12,21)( 9,13,14,10)(11,16,15,17)$
5A $5^{4},1$ $504$ $5$ $16$ $( 1, 9,10,11, 8)( 2,13,14,15,12)( 3, 4,19,21,18)( 5,20,17, 6,16)$
6A $6^{2},3,2^{2},1^{2}$ $210$ $6$ $14$ $( 1,14, 4,10, 2,19)( 3,21)( 6,17)( 7,13, 9)( 8,15,16,11,12,20)$
7A1 $7^{3}$ $360$ $7$ $18$ $( 1,13,17, 6, 7,19,18)( 2,14,21,11, 9,16, 3)( 4,12, 5,15,10,20, 8)$
7A-1 $7^{3}$ $360$ $7$ $18$ $( 1,18,19, 7, 6,17,13)( 2, 3,16, 9,11,21,14)( 4, 8,20,10,15, 5,12)$

Malle's constant $a(G)$:     $1/8$

magma: ConjugacyClasses(G);
 

Character table

1A 2A 3A 3B 4A 5A 6A 7A1 7A-1
Size 1 105 70 280 630 504 210 360 360
2 P 1A 1A 3A 3B 2A 5A 3A 7A1 7A-1
3 P 1A 2A 1A 1A 4A 5A 2A 7A-1 7A1
5 P 1A 2A 3A 3B 4A 1A 6A 7A-1 7A1
7 P 1A 2A 3A 3B 4A 5A 6A 1A 1A
Type
2520.a.1a R 1 1 1 1 1 1 1 1 1
2520.a.6a R 6 2 3 0 0 1 1 1 1
2520.a.10a1 C 10 2 1 1 0 0 1 ζ731ζ7ζ72 ζ73+ζ7+ζ72
2520.a.10a2 C 10 2 1 1 0 0 1 ζ73+ζ7+ζ72 ζ731ζ7ζ72
2520.a.14a R 14 2 1 2 0 1 1 0 0
2520.a.14b R 14 2 2 1 0 1 2 0 0
2520.a.15a R 15 1 3 0 1 0 1 1 1
2520.a.21a R 21 1 3 0 1 1 1 0 0
2520.a.35a R 35 1 1 1 1 0 1 0 0

magma: CharacterTable(G);
 

Regular extensions

Data not computed