The planar Turán number of $\{K_4,\hat{I}{˜}_6^i\}$

Jing Chen, Kai Gao, Yongxin Lan +2

Let $\mathcal{H}$ be a family of graphs. A graph is said to be $\mathcal{H}$-free if it contains no subgraph isomorphic to a graph in $\mathcal{H}$. The planar Turán number $ex_{_…