plot numerical question



I have a function

r4(s) := s!/(((s/4)!)^4 * 4^s)

and I am trying to plot it over the range [200,300]:

plot2d(r4(s), [s,200,300])

plot2d returns silently, i.e. it produces nothing.   I am 
fairly sure the problem is that the computation involves 
intermediate numbers that are too large, although the final 
result is well within the rang of an ordinary float.  E.g. 
r4(300) is of the order of 10^-4.

I thought I had seen a solution to this kind of problem with 
plot somewhere on the list, but I can't find it.   It seems 
to me the answer would be worth adding to the documentation 
for plotting.

(This is Maxima 5.17.1 using SBCL, same with CMUCL)

						Kostas