Order = 25545471085854720000 =
Mult = 2.
Out = 2.

Porting notes

Fully copied from version 2. 30/7/06.

Standard generators

Standard generators of A21 are a, b where a is in class 3A, b has order 19 and ab has order 21.

Standard generators of S21 are c, d where c is in the smallest conjugacy class of outer involutions, d has order 20 and cd has order 21.

Black box algorithms

Checking generators (semi-presentations)

Group Semi-presentation File
A21 〈〈 a, b | some conditions 〉〉 Download


Representations of A21

Representations of S21