TITLE: Painting the faces of a cube with distinct colours
QUESTION [21 upvotes]: I don't think this is solved by Burnside's Lemma since there is a condition that each side is painted a different colour. The question is as follows. 

If I had a cube and six colours, and painted each side a different colour, how many (different) ways could I paint the cube? What about if I had $n$ colours instead of 6?

The answer given in an old thread on a different site is $6!$ for the first question, and $n(n-1)(n-2)(n-3)(n-4)(n-5)$ for the second question. However, this doesn't actually hold up because a few of the paintings are isomorphic. The original thread assumes we can somehow tell the difference between two paintings which actually look identical if you rotate the cube, which I don't think is what the question intended.
The answer I got for the first question is $4! + 4 = 28$. But this was just through a case-bash, and I'm not sure whether it's correct or whether it generalizes.

REPLY [28 votes]: Case  $n=6$:  Colour one side with the ugliest colour, and put the cube on a table ugly side down. There are $5$ choices for the colour on top.  For each of these choices, colour the side facing you with the nicest remaining colour.  The last three sides can be coloured in $3!$ ways, so the number of colourings is $(5)(3!)$.
Case $n>6$: First choose the colours, then use them.  The number of colourings is
$$\binom{n}{6}(5)(3!).$$