Classification of 5-transitive groups by Ciro Santilli 34 Updated +Created
www.maths.qmul.ac.uk/~pjc/pps/pps9.pdf mentions:
The automorphism group of the extended Golay code is the 54-transitive Mathieu group . This is one of only two finite 5-transitive groups other than symmetric and alternating groups
Hmm, is that 54, or more likely 5 and 4?