Sample a known histogram of a population.

Say there nbuckets bins, and poptotal events.

When we sample a histogram, I think there are ... Some number of total ways to do it.  The poptotal.  So there are poptotal total options for the first sample and poptotal^samptotal total sampled histograms: and many of those histograms are identical, indicating they are more probable.

I am definitely making a number of weighted choices repeatedly.