Octahedral number
= Octahedral number
{wiki=Octahedral_number}
An octahedral number is a figurate number that represents a three-dimensional shape called an octahedron, which has eight triangular faces. The \\( n \\)-th octahedral number can be calculated using the formula: \\\[ O_n = \\frac\{n(2n^2 + 1)\}\{3\} \\\] where \\( n \\) is a positive integer.