Properties

Label 320.105.2.c1.a1
Order $ 2^{5} \cdot 5 $
Index $ 2 $
Normal Yes

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Subgroup ($H$) information

Description:$C_{20}:C_8$
Order: \(160\)\(\medspace = 2^{5} \cdot 5 \)
Index: \(2\)
Exponent: \(40\)\(\medspace = 2^{3} \cdot 5 \)
Generators: $ab, c^{4}, b^{4}, c^{5}, b^{6}c^{5}, c^{10}$ Copy content Toggle raw display
Derived length: $2$

The subgroup is characteristic (hence normal), maximal, nonabelian, metacyclic (hence solvable, supersolvable, monomial, and metabelian), and hyperelementary for $p = 2$.

Ambient group ($G$) information

Description: $C_{20}.D_8$
Order: \(320\)\(\medspace = 2^{6} \cdot 5 \)
Exponent: \(40\)\(\medspace = 2^{3} \cdot 5 \)
Derived length:$2$

The ambient group is nonabelian, supersolvable (hence solvable and monomial), hyperelementary for $p = 2$, and metabelian.

Quotient group ($Q$) structure

Description: $C_2$
Order: \(2\)
Exponent: \(2\)
Automorphism Group: $C_1$, of order $1$
Outer Automorphisms: $C_1$, of order $1$
Derived length: $1$

The quotient is cyclic (hence abelian, nilpotent, solvable, supersolvable, monomial, elementary, hyperelementary, metacyclic, metabelian, a Z-group, and an A-group), a $p$-group, simple, and rational.

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_5:(C_2\times C_4\times C_2^2.C_2^5)$
$\operatorname{Aut}(H)$ $C_2^3:D_4\times F_5$, of order \(1280\)\(\medspace = 2^{8} \cdot 5 \)
$\operatorname{res}(\operatorname{Aut}(G))$$D_{10}.C_2^5$, of order \(640\)\(\medspace = 2^{7} \cdot 5 \)
$\card{\operatorname{ker}(\operatorname{res})}$\(8\)\(\medspace = 2^{3} \)
$W$$C_5:D_4$, of order \(40\)\(\medspace = 2^{3} \cdot 5 \)

Related subgroups

Centralizer:$C_2\times C_4$
Normalizer:$C_{20}.D_8$
Minimal over-subgroups:$C_{20}.D_8$
Maximal under-subgroups:$C_4\times C_{20}$$C_{10}:C_8$$C_4:C_8$

Other information

Möbius function$-1$
Projective image$C_{10}.D_4$