Stirling Number - Stirling Numbers of The Second Kind

Stirling numbers of the second kind count the number of ways to partition a set of n elements into k nonempty subsets. They are denoted by or . The sum

is the nth Bell number.

Using falling factorials, we can characterize the Stirling numbers of the second kind by the identity

Read more about this topic:  Stirling Number

Famous quotes containing the words stirling, numbers and/or kind:

    Oh, if thy pride did not our joys control,
    What world of loving wonders shouldst thou see!
    For if I saw thee once transformed in me,
    Then in thy bosom I would pour my soul;
    William Alexander, Earl O Stirling (1580?–1640)

    All experience teaches that, whenever there is a great national establishment, employing large numbers of officials, the public must be reconciled to support many incompetent men; for such is the favoritism and nepotism always prevailing in the purlieus of these establishments, that some incompetent persons are always admitted, to the exclusion of many of the worthy.
    Herman Melville (1819–1891)

    And now, what will become of us without the barbarians?
    Those people were a kind of solution.
    Constantine Cavafy (1863–1933)