Feit-Thompson theorem

An important result in the classification of all finite simple groups, the Feit-Thompson theorem states that every non-Abelian simple group must have even order.

The only known proof requires 255 pages.

1 References

Feit, W. and Thompson, J. G., Solvability of groups of odd order, Pacific J. Math. 13 (1963), 775-1029.