Properties

Label 400.212.8.c1.a1
Order $ 2 \cdot 5^{2} $
Index $ 2^{3} $
Normal Yes

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Subgroup ($H$) information

Description:$C_5:D_5$
Order: \(50\)\(\medspace = 2 \cdot 5^{2} \)
Index: \(8\)\(\medspace = 2^{3} \)
Exponent: \(10\)\(\medspace = 2 \cdot 5 \)
Generators: $\left(\begin{array}{rrr} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 2 & 1 \end{array}\right), \left(\begin{array}{rrr} 1 & 4 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{array}\right), \left(\begin{array}{rrr} 1 & 0 & 0 \\ 0 & 4 & 0 \\ 0 & 2 & 1 \end{array}\right)$ Copy content Toggle raw display
Derived length: $2$

The subgroup is characteristic (hence normal), a semidirect factor, nonabelian, supersolvable (hence solvable and monomial), metabelian, and an A-group.

Ambient group ($G$) information

Description: $C_2\times C_5^2:Q_8$
Order: \(400\)\(\medspace = 2^{4} \cdot 5^{2} \)
Exponent: \(20\)\(\medspace = 2^{2} \cdot 5 \)
Derived length:$3$

The ambient group is nonabelian, monomial (hence solvable), and rational.

Quotient group ($Q$) structure

Description: $Q_8$
Order: \(8\)\(\medspace = 2^{3} \)
Exponent: \(4\)\(\medspace = 2^{2} \)
Automorphism Group: $S_4$, of order \(24\)\(\medspace = 2^{3} \cdot 3 \)
Outer Automorphisms: $S_3$, of order \(6\)\(\medspace = 2 \cdot 3 \)
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_{10}^2:\Unitary(2,3)$, of order \(9600\)\(\medspace = 2^{7} \cdot 3 \cdot 5^{2} \)
$\operatorname{Aut}(H)$ $C_5^2.\GL(2,5)$, of order \(12000\)\(\medspace = 2^{5} \cdot 3 \cdot 5^{3} \)
$\operatorname{res}(\operatorname{Aut}(G))$$C_5^2:\Unitary(2,3)$, of order \(2400\)\(\medspace = 2^{5} \cdot 3 \cdot 5^{2} \)
$\card{\operatorname{ker}(\operatorname{res})}$\(4\)\(\medspace = 2^{2} \)
$W$$C_5^2:Q_8$, of order \(200\)\(\medspace = 2^{3} \cdot 5^{2} \)

Related subgroups

Centralizer:$C_2$
Normalizer:$C_2\times C_5^2:Q_8$
Complements:$Q_8$ $Q_8$ $Q_8$ $Q_8$
Minimal over-subgroups:$C_5:D_{10}$
Maximal under-subgroups:$C_5^2$$D_5$$D_5$$D_5$

Other information

Möbius function$0$
Projective image$C_2\times C_5^2:Q_8$