20D10 16 finite group 14 finite groups 6 locally finite group 6 20D20 5 20D15 4 20F17 4 formation 4 05C25 3 20F16 3 20F50 3 Finite group 3 normal subgroup 3 supersoluble group 3 2 20D05 2 20D06 2 20D08 2 20D25 2 20D99 2 20E15 2 20F19 2 20F22 2 Fitting class 2 Sylow subgroup 2 \(\sigma\)-nilpotent group 2 \(\tau\)-closed formation 2 formation of finite groups 2 group 2 lattice of formations 2