Talk:Theorem on friends and strangers

Friendship theorem should not redirect to this page. The friendship theorem states that when you have n people, n at least four, and every two people have a unique friend in common (regardless of whether or not they are friends), the number of people is odd, and the configuration is as a windmill : one person is friends with everyone, all the others have exactly two friends. Here is a source : http://www.maths.qmul.ac.uk/~pjc/comb/ch11s.pdf Evilbu 20:25, 11 February 2006 (UTC)


 * I changed the redirect. —David Eppstein (talk) 03:10, 24 January 2010 (UTC)

caption of image on K6 colourings
I edited the caption, please note that the total number of colourings may be incorrect because I forgot to include the possibility of edge-colourings with all red (or blue) edges forming a self-complementary graph which would make the red/blue complement of the Kn edge colouring the same as before, will look into it ASAP. 84.255.33.196 (talk) 17:20, 28 June 2022 (UTC)