Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #11 Jun 25 2022 17:07:13
%S 0,0,0,1,2,4,6,8,12,16,20,26
%N Maximum number of edges a single edge crosses in a drawing of the complete graph K_n where every vertex lies on the outer face.
%e 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.
%K nonn,more
%O 1,5
%A _Sam Barr_, Jul 13 2021