Properties

Label 2156.g.22.a1.a1
Order $ 2 \cdot 7^{2} $
Index $ 2 \cdot 11 $
Normal Yes

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Subgroup ($H$) information

Description:$C_7\times C_{14}$
Order: \(98\)\(\medspace = 2 \cdot 7^{2} \)
Index: \(22\)\(\medspace = 2 \cdot 11 \)
Exponent: \(14\)\(\medspace = 2 \cdot 7 \)
Generators: $a^{14}, b^{22}, a^{4}$ Copy content Toggle raw display
Nilpotency class: $1$
Derived length: $1$

The subgroup is characteristic (hence normal), abelian (hence nilpotent, solvable, supersolvable, monomial, metabelian, and an A-group), elementary for $p = 7$ (hence hyperelementary), and metacyclic.

Ambient group ($G$) information

Description: $C_{77}:C_{28}$
Order: \(2156\)\(\medspace = 2^{2} \cdot 7^{2} \cdot 11 \)
Exponent: \(308\)\(\medspace = 2^{2} \cdot 7 \cdot 11 \)
Derived length:$2$

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

Quotient group ($Q$) structure

Description: $D_{11}$
Order: \(22\)\(\medspace = 2 \cdot 11 \)
Exponent: \(22\)\(\medspace = 2 \cdot 11 \)
Automorphism Group: $F_{11}$, of order \(110\)\(\medspace = 2 \cdot 5 \cdot 11 \)
Outer Automorphisms: $C_5$, of order \(5\)
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)$$C_{77}.C_{15}.C_6.C_2^3$
$\operatorname{Aut}(H)$ $\GL(2,7)$, of order \(2016\)\(\medspace = 2^{5} \cdot 3^{2} \cdot 7 \)
$\operatorname{res}(\operatorname{Aut}(G))$$C_6^2$, of order \(36\)\(\medspace = 2^{2} \cdot 3^{2} \)
$\card{\operatorname{ker}(\operatorname{res})}$\(1540\)\(\medspace = 2^{2} \cdot 5 \cdot 7 \cdot 11 \)
$W$$C_2$, of order \(2\)

Related subgroups

Centralizer:$C_7\times C_{154}$
Normalizer:$C_{77}:C_{28}$
Minimal over-subgroups:$C_7\times C_{154}$$C_7:C_{28}$
Maximal under-subgroups:$C_7^2$$C_{14}$$C_{14}$$C_{14}$$C_{14}$$C_{14}$

Other information

Möbius function$11$
Projective image$D_{77}$