Properties

Label 128.925.8.c1.a1
Order $ 2^{4} $
Index $ 2^{3} $
Normal Yes

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Subgroup ($H$) information

Description:$\OD_{16}$
Order: \(16\)\(\medspace = 2^{4} \)
Index: \(8\)\(\medspace = 2^{3} \)
Exponent: \(8\)\(\medspace = 2^{3} \)
Generators: $bc^{2}d, c^{4}d$ Copy content Toggle raw display
Nilpotency class: $2$
Derived length: $2$

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

Ambient group ($G$) information

Description: $D_4.D_8$
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: $D_4$
Order: \(8\)\(\medspace = 2^{3} \)
Exponent: \(4\)\(\medspace = 2^{2} \)
Automorphism Group: $D_4$, of order \(8\)\(\medspace = 2^{3} \)
Outer Automorphisms: $C_2$, of order \(2\)
Nilpotency class: $2$
Derived length: $2$

The quotient is nonabelian, a $p$-group (hence nilpotent, solvable, supersolvable, monomial, elementary, and hyperelementary), metacyclic (hence metabelian), 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_4^3.C_2^3$, of order \(512\)\(\medspace = 2^{9} \)
$\operatorname{Aut}(H)$ $C_2\times D_4$, of order \(16\)\(\medspace = 2^{4} \)
$\operatorname{res}(\operatorname{Aut}(G))$$C_2\times D_4$, of order \(16\)\(\medspace = 2^{4} \)
$\card{\operatorname{ker}(\operatorname{res})}$\(32\)\(\medspace = 2^{5} \)
$W$$C_2\times D_4$, of order \(16\)\(\medspace = 2^{4} \)

Related subgroups

Centralizer:$C_8$
Normalizer:$D_4.D_8$
Minimal over-subgroups:$\OD_{16}:C_2$$Q_{16}:C_2$$\OD_{16}:C_2$
Maximal under-subgroups:$C_2\times C_4$$C_8$

Other information

Möbius function$0$
Projective image$D_4:D_4$