Python is currently failing with what appears to be an error in the reference solution (see spoiler comment below).

In Python, import fractions yields fractions == None. This does not seem to be intentional, so I'm assuming something in the import-prevention stuff is broken.

Should be posted under "Issues"

:/

Like @crunker99 said above, it's worth noting that this evaluates the expression for every single day. Fine in this case because they're all very cheap, but something to keep in mind.

@dfhwze I think k == 0 is reachable iff n == 0. (Take a look at my solution to the current version.)

outcome(0, 8, 0) is expected to equal 0, not 1, which is confusing since summing up zero 8-sided dice will always result in a sum of zero (by the usual convention that the empty sum is zero). The intended behavior for n == 0 should be clarified in the description.

s sides numbered from 1 to s

The description needs to clarify what should happen when s = 0.

In Python specifically, outcome({s}, {n}, {k}) should be outcome({n}, {s}, {k})

The Python description code blocks are written in Javascript.

Because of the sorted bit, a == c means a == b == c, so the equilateral condition can be a == c and the isosceles condition can be a == b or b == c.

Since this is the top answer on a high-kyu kata, I'll mention that using this level of precision is pointless (from a programming perspective), because nearly all of it will be lost (double-precision floats only have ~16 decimal digits of accuracy).