No account of the symmetric group can be complete without mentioning the remarkable fact that the symmetric group of degree n (finite or infinite) has an outer automorphism if and only if n=6. Here are the definitions. An automorphism of a group G is a permutation p of the group which preserves products, that is,…
The NeoCube is an entertainment device like no other in the world.
Composed of 216 individual high-energy rare-earth magnets, the NeoCube allows you to create and recreate an outrageous number of shapes and patterns.