The Bell number Bn counts the number of different ways to partition a set that has exactly n elements, or equivalently, the number of equivalence relations on it . Bn also counts the number of different rhyme schemes for n-line poems.
The Bell number Bn counts the number of different ways to partition a set that has exactly n elements, or equivalently, the number of equivalence relations on it . Bn also counts the number of different rhyme schemes for n-line poems.