OFFSET
1,5
EXAMPLE
K_1, K_2, K_3 are all outerplanar graphs, and therefore have no crossings. K_4 can be drawn as a box with one crossing inside the box. K_5 can be drawn as a pentagram inside a pentagon, and in a drawing of a pentagram any edge crosses only two other edges.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Sam Barr, Jul 13 2021
STATUS
approved