- graph6 and digraph6 : http://users.cecs.anu.edu.au/~bdm/data/formats.txt
- query for House of Graphs : https://hog.grinvin.org/
- edge-connectivity
- minimum degree
- maximum degree
- select a set and make a complement :
- girth
- is eulerian?
- show a spanning tree on the picture
- Hard Stuff:
- chromatic index/number : chromatic_number() and chromatic_index()
- hamiltonicity : is_hamiltonian()
- vertex-connectivity