Antiprism

Antiprism --- антипризма.

The antiprism [math]\displaystyle{ A_{n} }[/math], [math]\displaystyle{ n \geq 3 }[/math], is the plane regular graph of degree 4 (an Archimedean convex polytope). In particular, [math]\displaystyle{ A_{3} }[/math] is the octahedron.

The [math]\displaystyle{ k }[/math]-antiprism is the 4-regular plane graph consisting of two [math]\displaystyle{ k }[/math]-gons and [math]\displaystyle{ 2k }[/math] triangles such that every vertex is incident with three triangles and one [math]\displaystyle{ k }[/math]-gon.