mathjs/docs/reference/functions/stirlingS2.md

Function stirlingS2

The Stirling numbers of the second kind, counts the number of ways to partition a set of n labelled objects into k nonempty unlabelled subsets. stirlingS2 only takes integer arguments. The following condition must be enforced: k <= n.

If n = k or k = 1, then s(n,k) = 1

Syntax

math.stirlingS2(n, k)

Parameters

Parameter	Type	Description
n	Number | BigNumber	Total number of objects in the set
k	Number | BigNumber	Number of objects in the subset

Returns

Type	Description
Number | BigNumber	S(n,k)

Examples

math.stirlingS2(5, 3); //returns 25

See also

[Bell numbers](Bell numbers.md)