Definition:Heptagonal Number

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

They can be denoted:
 * $H_1, H_2, H_3, \ldots$

Also known as
Heptagonal numbers are also known as heptagon numbers.

Or we can just say that a number is heptagonal.

Some sources denote the $n$th heptagonal number as $\map H n$ in preference to $H_n$.

Also see

 * Equivalence of Definitions of Heptagonal Number


 * Closed Form for Heptagonal Numbers: $H_n = \dfrac {n \paren {5 n - 3} } 2$


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