bell {numbers} | R Documentation |
Bell Numbers
Description
Generate Bell numbers.
Usage
bell(n)
Arguments
n |
integer, asking for the n-th Bell number. |
Details
Bell numbers, commonly denoted as , are defined as the number of
partitions of a set of
n
elements. They can easily be calculated
recursively.
Bell numbers also appear as moments of probability distributions, for example
B_n
is the n-th momentum of the Poisson distribution with mean 1.
Value
A single integer, as long as n<=22
.
Examples
sapply(0:10, bell)
# 1 1 2 5 15 52 203 877 4140 21147 115975
[Package numbers version 0.8-5 Index]