Total Number of Set Partitions/Examples

Examples of Total Number of Set Partitions

Example: $\card S = 2$

Let $S$ be a set whose cardinality is $2$.

Then the number of partitions of $S$ is $2$.

Example: $\card S = 3$

Let $S$ be a set whose cardinality is $3$.

Then the number of partitions of $S$ is $5$.

Example: $\card S = 4$

Let $S$ be a set whose cardinality is $4$.

Then the number of partitions of $S$ is $15$.