Definition:Octagonal Number

Definition
Octagonal numbers are those denumerating a collection of objects which can be arranged in the form of a regular octagon.

They can be denoted:
 * $O_1, O_2, O_3, \ldots$

Also known as
Octagonal numbers are also known as octagon numbers.

Or we can just say that a number is octagonal.

Also see

 * Equivalence of Definitions of Octagonal Number


 * Closed Form for Octagonal Numbers: $O_n = n \left({3 n - 2}\right)$


 * Definition:Polygonal Number:
 * Definition:Triangular Number
 * Definition:Square Number
 * Definition:Pentagonal Number
 * Definition:Hexagonal Number