Crown

Crown --- корона.

For positive integers [math]\displaystyle{ k \leq n }[/math], the crown [math]\displaystyle{ C_{n,k} }[/math] is a graph with a vertex set [math]\displaystyle{ \{a_{1}, \ldots, a_{n}, b_{1}, \ldots, b_{n}\} }[/math] and an edge set [math]\displaystyle{ \{a_{i}b_{j}: \; 1 \leq i \leq n, j = i+1, i+2, \ldots, i+k-1 \pmod{n}\} }[/math].