Graph of 14 (3-valent) vertices, 20 edges,
and of interesting symmetry.
It is a (3,6)-cage: the smallest cubic graph with girth 6.
Percy Heawood (1861--1955, England) spent most of his life working on the four colour problem. Studied also continued fractions. Considered to be extravagant with his immense moustache, an indispensable ancient handbag, and often accompanied by a dog, which was admitted to his lectures.
The harmonic evolution digraph consists of:
| Loops | = | 64 L1 + 2016 L2 | |
| Tree | = | T2 |