Dihedral group:D20

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This article is about a particular group, i.e., a group unique upto isomorphism. View specific information (such as linear representation theory, subgroup structure) about this group
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Definition

This group is defined in the following equivalent ways:

  1. It is the dihedral group of order 20.
  2. It is the direct product of the dihedral group of order ten and the cyclic group of order two.

Arithmetic functions

Function Value Explanation
order 20
exponent 10
Frattini length 1
Fitting length 1
derived length 2

Group properties

Property Satisfied Explanation
cyclic group No
abelian group No
metacyclic group Yes
supersolvable group Yes
solvable group Yes

GAP implementation

Group ID

This finite group has order 20 and has ID 4 among the groups of order 20 in GAP's SmallGroup library. For context, there are 5 groups of order 20. It can thus be defined using GAP's SmallGroup function as:

SmallGroup(20,4)

For instance, we can use the following assignment in GAP to create the group and name it G:

gap> G := SmallGroup(20,4);

Conversely, to check whether a given group G is in fact the group we want, we can use GAP's IdGroup function:

IdGroup(G) = [20,4]

or just do:

IdGroup(G)

to have GAP output the group ID, that we can then compare to what we want.