20 Sep
2018
20 Sep
'18
11:03 p.m.
That sounds like the checkerboard lattice D_n in n-space, D_n = {(x_1, ..., x_n) in Z^n | x_1 + ... + x_n == 0 mod 2} —Dan ----- the unit-sphere packing where centres have evenly many odd integer Cartesian components. -----