Published online by Cambridge University Press: 17 August 2018
We extend known results concerning crossing numbers by giving the crossing number of the join product $G+D_{n}$, where the connected graph $G$ consists of one $4$-cycle and of two leaves incident with the same vertex of the $4$-cycle, and $D_{n}$ consists of $n$ isolated vertices. The proofs are done with the help of software that generates all cyclic permutations for a given number $k$ and creates a graph for calculating the distances between all $(k-1)!$ vertices of the graph.
The research was supported by the internal faculty research project no. FEI-2017-39.