![https://commons.wikimedia.org/wiki/File:Harborth_graph_vector.svg](https://www.futilitycloset.com/wp-content/uploads/2021/12/2021-12-16-network.png)
I’m just sharing this because I think it’s pretty — it’s the smallest arrangement of identical non-crossing matchsticks that one can make on a tabletop in which each match-end touches three others.
Presented by German mathematician Heiko Harborth in 1986, it’s known as the Harborth graph.