Groups whose commutator structure agrees: there are isomorphisms G/Z(G) → H/Z(H) and G′ → H′ carrying one commutator map to the other. The class spans orders — G × A is isoclinic to G for every abelian A.
Stem order 39: every member's order is a multiple of it, and the members attaining it — the stem groups — are marked ◆.
643 groups of the catalog are in this class; the 639 with an abelian direct factor are hidden.
| group | order | × stem | |
|---|---|---|---|
| C13⋊C3 | 39 | ×1 | ◆ stem |
| C13⋊C9 | 117 | ×3 | |
| C13⋊C27 | 351 | ×9 | |
| C13⋊C81 | 1,053 | ×27 |
The class itself is infinite — G × A is isoclinic to G for every abelian A, and there are abelian groups of every order — so a table shows the part of it the catalog names, never the whole.