The Cohomology of the Sylow 2-subgroup of the Higman-Sims Group
  In this paper we compute the mod 2 cohomology of the Sylow 2-subgroup of the Higman-Sims group HS, one of the 26 sporadic simple groups. We obtain its Poincare series as well as an explicit description of it as a ring with 17 generators and 79 relations 
Alejandro Adem, Jon F.Carlson, Dikran Karagueuzian and R.James Milgram