User blog comment:I am a McCree God/Number of Possible Combinations in 1,000,000x1,000,000x1,000,000 Rubik's Cube/@comment-5529393-20171215043217/@comment-32876686-20171215163739

It was most likely the first one:

\(\frac{(24\cdot 2^{10}\cdot12!)^{\text{n mod 2}}\cdot 7!\cdot 3^6\cdot(24!)^{\floor{\frac{n^2-2n}{4}}}}{(4!)^{6\floor{\frac{(n-2)^2}{4}}}\)

The second formula was referring to the number of combinations in a supercube, or a cube in which the positions of the centers matter as well.