+A hexagonal number maps the dots forming a regular hexagon. These [Polygonal Number](/wiki/Polygonal_Number)s grow by adding layers, each a sum of the previous and a new row, much like a [Triangular Number](/wiki/Triangular_Number) expands.
+## See also
+- [Polygonal Number](/wiki/Polygonal_Number)
+- [Triangular Number](/wiki/Triangular_Number)
+- [Square Number](/wiki/Square_Number)
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