Properties

Label 21T4
21T4 1 4 1->4 9 1->9 2 5 2->5 8 2->8 3 6 3->6 7 3->7 4->8 17 4->17 5->7 18 5->18 6->9 16 6->16 7->4 11 7->11 8->6 12 8->12 9->5 10 9->10 13 10->13 14 10->14 11->14 15 11->15 12->13 12->15 13->2 13->17 14->1 14->16 15->3 15->18 16->12 20 16->20 17->11 21 17->21 18->10 19 18->19 19->1 19->21 20->2 20->19 21->3 21->20
Degree $21$
Order $42$
Cyclic no
Abelian no
Solvable yes
Primitive no
$p$-group no
Group: $F_7$

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Copy content magma:G := TransitiveGroup(21, 4);
 

Group invariants

Abstract group:  $F_7$
Copy content magma:IdentifyGroup(G);
 
Order:  $42=2 \cdot 3 \cdot 7$
Copy content magma:Order(G);
 
Cyclic:  no
Copy content magma:IsCyclic(G);
 
Abelian:  no
Copy content magma:IsAbelian(G);
 
Solvable:  yes
Copy content magma:IsSolvable(G);
 
Nilpotency class:   not nilpotent
Copy content magma:NilpotencyClass(G);
 

Group action invariants

Degree $n$:  $21$
Copy content magma:t, n := TransitiveGroupIdentification(G); n;
 
Transitive number $t$:  $4$
Copy content magma:t, n := TransitiveGroupIdentification(G); t;
 
Parity:  $-1$
Copy content magma:IsEven(G);
 
Primitive:  no
Copy content magma:IsPrimitive(G);
 
$\card{\Aut(F/K)}$:  $3$
Copy content magma:Order(Centralizer(SymmetricGroup(n), G));
 
Generators:  $(1,9,5,18,10,14)(2,8,6,16,12,13)(3,7,4,17,11,15)(19,21,20)$, $(1,4,8,12,15,18,19)(2,5,7,11,14,16,20)(3,6,9,10,13,17,21)$
Copy content magma:Generators(G);
 

Low degree resolvents

$\card{(G/N)}$Galois groups for stem field(s)
$2$:  $C_2$
$3$:  $C_3$
$6$:  $C_6$

Resolvents shown for degrees $\leq 47$

Subfields

Degree 3: $C_3$

Degree 7: $F_7$

Low degree siblings

7T4, 14T4, 42T4

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 $2^{9},1^{3}$ $7$ $2$ $9$ $( 1,12)( 2,11)( 3,10)( 4, 8)( 5, 7)( 6, 9)(13,21)(14,20)(15,19)$
3A1 $3^{7}$ $7$ $3$ $14$ $( 1,21, 7)( 2,19, 9)( 3,20, 8)( 4,10,14)( 5,12,13)( 6,11,15)(16,18,17)$
3A-1 $3^{7}$ $7$ $3$ $14$ $( 1, 7,21)( 2, 9,19)( 3, 8,20)( 4,14,10)( 5,13,12)( 6,15,11)(16,17,18)$
6A1 $6^{3},3$ $7$ $6$ $17$ $( 1, 5,21,12, 7,13)( 2, 6,19,11, 9,15)( 3, 4,20,10, 8,14)(16,17,18)$
6A-1 $6^{3},3$ $7$ $6$ $17$ $( 1,13, 7,12,21, 5)( 2,15, 9,11,19, 6)( 3,14, 8,10,20, 4)(16,18,17)$
7A $7^{3}$ $6$ $7$ $18$ $( 1,15, 4,18, 8,19,12)( 2,14, 5,16, 7,20,11)( 3,13, 6,17, 9,21,10)$

Malle's constant $a(G)$:     $1/9$

Copy content magma:ConjugacyClasses(G);
 

Character table

1A 2A 3A1 3A-1 6A1 6A-1 7A
Size 1 7 7 7 7 7 6
2 P 1A 1A 3A-1 3A1 3A1 3A-1 7A
3 P 1A 2A 1A 1A 2A 2A 7A
7 P 1A 2A 3A1 3A-1 6A1 6A-1 1A
Type
42.1.1a R 1 1 1 1 1 1 1
42.1.1b R 1 1 1 1 1 1 1
42.1.1c1 C 1 1 ζ31 ζ3 ζ3 ζ31 1
42.1.1c2 C 1 1 ζ3 ζ31 ζ31 ζ3 1
42.1.1d1 C 1 1 ζ31 ζ3 ζ3 ζ31 1
42.1.1d2 C 1 1 ζ3 ζ31 ζ31 ζ3 1
42.1.6a R 6 0 0 0 0 0 1

Copy content magma:CharacterTable(G);
 

Regular extensions

Data not computed