The Octad Graph
win.tue.nl
win.tue.nl
[1] https://en.wikipedia.org/wiki/J-invariant
[2] https://en.wikipedia.org/wiki/Steiner_system
[3] https://en.wikipedia.org/wiki/Binary_Golay_code
[4] https://en.wikipedia.org/wiki/Mathieu_group_M24
[5] https://en.wikipedia.org/wiki/Leech_lattice
[6] https://en.wikipedia.org/wiki/Monster_group
[7] https://en.wikipedia.org/wiki/Monstrous_moonshine