construct/nppc clique

The task

Undirected graph with 20 vertices labelled 0..19 and 122 edges: [[0, 1], [0, 2], [0, 3], [0, 6], [0, 9], [0, 10], [0, 11], [0, 12], [0, 15], [1, 3], [1, 4], [1, 6], [1, 7], [1, 8], [1, 9], [1, 10], [1, 11], [1, 13], [1, 14], [1, 15], [1, 16], [1, 17], [1, 18], [1, 19], [2, 6], [2, 9], [2, 10], [2, 13], [2, 15], [2,…