Properties

Label 490.9.10.a1.a1
Order $ 7^{2} $
Index $ 2 \cdot 5 $
Normal Yes

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Subgroup ($H$) information

Description:$C_7^2$
Order: \(49\)\(\medspace = 7^{2} \)
Index: \(10\)\(\medspace = 2 \cdot 5 \)
Exponent: \(7\)
Generators: $b, c^{5}$ Copy content Toggle raw display
Nilpotency class: $1$
Derived length: $1$

The subgroup is characteristic (hence normal), a semidirect factor, abelian (hence nilpotent, solvable, supersolvable, monomial, metabelian, and an A-group), a $7$-Sylow subgroup (hence a Hall subgroup), a $p$-group (hence elementary and hyperelementary), and metacyclic.

Ambient group ($G$) information

Description: $C_7:D_{35}$
Order: \(490\)\(\medspace = 2 \cdot 5 \cdot 7^{2} \)
Exponent: \(70\)\(\medspace = 2 \cdot 5 \cdot 7 \)
Derived length:$2$

The ambient group is nonabelian, supersolvable (hence solvable and monomial), metabelian, and an A-group.

Quotient group ($Q$) structure

Description: $D_5$
Order: \(10\)\(\medspace = 2 \cdot 5 \)
Exponent: \(10\)\(\medspace = 2 \cdot 5 \)
Automorphism Group: $F_5$, of order \(20\)\(\medspace = 2^{2} \cdot 5 \)
Outer Automorphisms: $C_2$, of order \(2\)
Nilpotency class: $-1$
Derived length: $2$

The quotient is nonabelian, a Z-group (hence solvable, supersolvable, monomial, metacyclic, metabelian, and an A-group), and hyperelementary for $p = 2$.

Automorphism information

Since the subgroup $H$ is characteristic, the automorphism group $\operatorname{Aut}(G)$ of the ambient group acts on $H$, yielding a homomorphism $\operatorname{res} : \operatorname{Aut}(G) \to \operatorname{Aut}(H)$. The image of $\operatorname{res}$ on the inner automorphism group $\operatorname{Inn}(G)$ is the Weyl group $W = G / Z_G(H)$.

$\operatorname{Aut}(G)$$F_5\times C_7^2:C_3.\SL(2,7).C_2$
$\operatorname{Aut}(H)$ $\GL(2,7)$, of order \(2016\)\(\medspace = 2^{5} \cdot 3^{2} \cdot 7 \)
$\operatorname{res}(\operatorname{Aut}(G))$$\GL(2,7)$, of order \(2016\)\(\medspace = 2^{5} \cdot 3^{2} \cdot 7 \)
$\card{\operatorname{ker}(\operatorname{res})}$\(980\)\(\medspace = 2^{2} \cdot 5 \cdot 7^{2} \)
$W$$C_2$, of order \(2\)

Related subgroups

Centralizer:$C_7\times C_{35}$
Normalizer:$C_7:D_{35}$
Complements:$D_5$
Minimal over-subgroups:$C_7\times C_{35}$$C_7:D_7$
Maximal under-subgroups:$C_7$$C_7$$C_7$$C_7$$C_7$$C_7$$C_7$$C_7$

Other information

Möbius function$5$
Projective image$C_7:D_{35}$