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From: facc005@SAUPM00.BITNET ("M. Atiquzzaman")
Newsgroups: comp.theory
Subject: partitioning problem
Message-ID: <9011301618.AA00954@irt.watson.ibm.com>
Date: 30 Nov 90 16:18:41 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: "M. Atiquzzaman" <facc005%SAUPM00.BITNET@VM1.NoDak.EDU>
Lines: 12

The number of ways of partitioning n objects into k groups such
that * no group is empty * is given by the Stirling's number of the
second type i.e.

S(n,k) = S(n-1,k-1) + k*S(n-1,k)

Is there any formula for calculating the number of possible partitions
if * one or more groups may be empty *  ?

M. Atiquzzaman
facc005@saupm00.bitnet
facc005%saupm00.bitnet@cunyvm.cuny.edu