7
$\begingroup$

Stirling numbers of the second kind S(n, k) count the number of ways to partition a set of n elements into k nonempty subsets.What if there were duplicate elements in the set?That is,the set is a multiset?

  • 0
    It would be good to add the link to the definition of Stirling numbers: http://en.wikipedia.org/wiki/Stirling_numbers_of_the_second_kind2011-01-09
  • 1
    The answer is likely to be somewhat complicated to express. For example, if the set consists of a single type of element, you get the partition numbers p_{n,k} : http://en.wikipedia.org/wiki/Partition_(number_theory)2011-01-09
  • 2
    I think [math] is a pretty useless tag in this site; I've deleted it and added [counting]2011-01-10

4 Answers 4