These are one type of 2-dimensional figurate numbers. A hexagonal number is a figurate number. The Pythagorean tradition spoke also of so-called polygonal or figurate numbers. He also implements the use of figurate numbers in interpreting Torah verses. Figurate numbers were a concern of Pythagorean geometry. Many other figurate numbers can be expressed as Ehrhart polynomials. Figurate numbers have played a significant role in modern recreational mathematics. A dodecahedral number is a figurate number that represents a dodecahedron. A heptagonal number is a figurate number that represents a heptagon. An octagonal number is a figurate number that represents an octagon. A dodecagonal number is a figurate number that represents a dodecagon. An icosahedral number is a figurate number that represents an icosahedron. Figurate numbers representing pentagons (including five) are called pentagonal numbers. Figurate numbers representing hexagons (including six) are called hexagonal numbers. In modern mathematics, figurate numbers are formalized by the Ehrhart polynomials.