Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A hexagonal number is a figurate number, The nth hexagonal number will be the number of points in a hexagon with n regularly spaced points on a side. Hexagonal numbers can be rearranged into rectangular numbers n long and 2n 1 tall (or vice versa). Hexagonal numbers should not be confused with centered hexagonal numbers, which model the standard packaging of Vienna sausages. To avoid ambiguity, hexagonal numbers are sometimes called "cornered hexagonal numbers".