In order to show a Lattice is a Boolean Algebra, the diagram needs to be bounded, distributive, complemented, and $\displaystyle |L|=2^n \ n\geq 1 \ n\in\mathbb{Z}$.

However, my book says, "A finite lattice is called a Boolean Algebra if it is isomorphic to $\displaystyle B_n$ for some nonnegative integer n."

What is $\displaystyle B_n$?

I know $\displaystyle D_n$ are the numbers that divide n but have no clue about this $\displaystyle B_n$.

Thanks.