Properties

Label 400.212.25.a1.a1
Order $ 2^{4} $
Index $ 5^{2} $
Normal No

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Subgroup ($H$) information

Description:$C_2\times Q_8$
Order: \(16\)\(\medspace = 2^{4} \)
Index: \(25\)\(\medspace = 5^{2} \)
Exponent: \(4\)\(\medspace = 2^{2} \)
Generators: $\left(\begin{array}{rrr} 4 & 3 & 3 \\ 0 & 1 & 0 \\ 1 & 0 & 1 \end{array}\right), \left(\begin{array}{rrr} 4 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 3 & 4 \end{array}\right), \left(\begin{array}{rrr} 3 & 0 & 0 \\ 0 & 1 & 0 \\ 2 & 1 & 2 \end{array}\right), \left(\begin{array}{rrr} 4 & 0 & 0 \\ 0 & 4 & 0 \\ 0 & 0 & 4 \end{array}\right)$ Copy content Toggle raw display
Nilpotency class: $2$
Derived length: $2$

The subgroup is maximal, nonabelian, a $2$-Sylow subgroup (hence nilpotent, solvable, supersolvable, a Hall subgroup, and monomial), a $p$-group (hence elementary and hyperelementary), metabelian, and rational.

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.

Automorphism information

While the subgroup $H$ is not characteristic, the stabilizer $S$ of $H$ in the automorphism group $\operatorname{Aut}(G)$ of the ambient group acts on $H$, yielding a homomorphism $\operatorname{res} : S \to \operatorname{Aut}(H)$. The image of $\operatorname{res}$ on the inner automorphisms $\operatorname{Inn}(G) \cap S$ is the Weyl group $W = N_G(H) / Z_G(H)$.

$\operatorname{Aut}(G)$$C_{10}^2:\Unitary(2,3)$, of order \(9600\)\(\medspace = 2^{7} \cdot 3 \cdot 5^{2} \)
$\operatorname{Aut}(H)$ $C_2^3:S_4$, of order \(192\)\(\medspace = 2^{6} \cdot 3 \)
$\operatorname{res}(S)$$C_2^2:S_4$, of order \(96\)\(\medspace = 2^{5} \cdot 3 \)
$\card{\operatorname{ker}(\operatorname{res})}$\(4\)\(\medspace = 2^{2} \)
$W$$C_2^2$, of order \(4\)\(\medspace = 2^{2} \)

Related subgroups

Centralizer:$C_2^2$
Normalizer:$C_2\times Q_8$
Normal closure:$C_2\times C_5^2:Q_8$
Core:$C_2$
Minimal over-subgroups:$C_2\times C_5^2:Q_8$
Maximal under-subgroups:$C_2\times C_4$$C_2\times C_4$$C_2\times C_4$$Q_8$$Q_8$$Q_8$$Q_8$

Other information

Number of subgroups in this conjugacy class$25$
Möbius function$-1$
Projective image$C_5^2:Q_8$