StirlingS2

StirlingS2[n,m]

gives the Stirling number of the second kind .

Details

  • Integer mathematical function, suitable for both symbolic and numerical manipulation.
  • gives the number of ways of partitioning a set of elements into nonempty subsets.
  • StirlingS2 automatically threads over lists.

Examples

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Basic Examples  (1)

Scope  (2)

StirlingS2 threads element-wise over lists:

TraditionalForm formatting:

Applications  (4)

Plot Stirling numbers of the second kind on a logarithmic scale:

Stirling numbers modulo 2:

Closed form of derivatives of compositions with exponential functions:

A fair sided die is thrown times independently. The probability that all faces appear at least once is given in terms of Stirling numbers of the second kind:

Plot the probability for a six-sided die:

Check with simulations:

Properties & Relations  (6)

Generate values from the generating function:

Stirling numbers of the second kind are effectively inverses of Stirling numbers of the first kind:

Calculate large Stirling numbers of the second kind using Cauchy's theorem:

Generate Stirling numbers of the second kind from the commutation relation :

The limit of finite differences of powers are Stirling numbers of the second kind:

Stirling numbers of the second kind are given by a partial Bell polynomial with unit arguments:

Possible Issues  (2)

StirlingS2 can take large values for moderatesize arguments:

The value at is defined to be 1:

Neat Examples  (2)

Plot sums of digits:

Introduced in 1988
 (1.0)