Source: wikibot/ordered-bell-number
= Ordered Bell number
{wiki=Ordered_Bell_number}
The Ordered Bell number is a concept in combinatorial mathematics that counts the number of ways to partition a set into a certain number of non-empty ordered subsets. More formally, the \\( n \\)-th Ordered Bell number, denoted as \\( B_n^\{o\} \\), gives the number of ways to partition a set of size \\( n \\) into \\( k \\) non-empty subsets, where the order of the subsets matters.