Properties

Label 128.68.1.a1.a1
Order $ 2^{7} $
Index $ 1 $
Normal Yes

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Subgroup ($H$) information

Description:$D_8:C_8$
Order: \(128\)\(\medspace = 2^{7} \)
Index: $1$
Exponent: \(16\)\(\medspace = 2^{4} \)
Generators: $a, b$ Copy content Toggle raw display
Nilpotency class: $4$
Derived length: $2$

The subgroup is the Fitting subgroup (hence characteristic, normal, nilpotent, solvable, supersolvable, and monomial), the radical, a direct factor, nonabelian, a $2$-Sylow subgroup (hence a Hall subgroup), a $p$-group (hence elementary and hyperelementary), and metabelian.

Ambient group ($G$) information

Description: $D_8:C_8$
Order: \(128\)\(\medspace = 2^{7} \)
Exponent: \(16\)\(\medspace = 2^{4} \)
Nilpotency class:$4$
Derived length:$2$

The ambient group is nonabelian, a $p$-group (hence nilpotent, solvable, supersolvable, monomial, elementary, and hyperelementary), and metabelian.

Quotient group ($Q$) structure

Description: $C_1$
Order: $1$
Exponent: $1$
Automorphism Group: $C_1$, of order $1$
Outer Automorphisms: $C_1$, of order $1$
Nilpotency class: $0$
Derived length: $0$

The quotient is cyclic (hence abelian, nilpotent, solvable, supersolvable, monomial, elementary (for every $p$), hyperelementary, metacyclic, metabelian, a Z-group, and an A-group), a $p$-group (for every $p$), perfect, 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_4^2.C_2^4$, of order \(256\)\(\medspace = 2^{8} \)
$\operatorname{Aut}(H)$ $C_4^2.C_2^4$, of order \(256\)\(\medspace = 2^{8} \)
$W$$D_4:C_4$, of order \(32\)\(\medspace = 2^{5} \)

Related subgroups

Centralizer:$C_4$
Normalizer:$D_8:C_8$
Complements:$C_1$
Maximal under-subgroups:$D_8:C_4$$C_8:C_8$$C_8.C_8$

Other information

Möbius function$1$
Projective image$D_4:C_4$