Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!genrad!decvax!watmath!ljdickey From: ljdickey@watmath.UUCP Newsgroups: net.math Subject: stuff Message-ID: <5376@watmath.UUCP> Date: Fri, 10-Jun-83 16:16:05 EDT Article-I.D.: watmath.5376 Posted: Fri Jun 10 16:16:05 1983 Date-Received: Sat, 11-Jun-83 20:11:35 EDT Lines: 18 OK, Dean Hoffman has solved your puzzle. Here are two graphs, each with 9 vertices. That means there are 36 pairs of vertices. Each of them has 12 pairs with distance 2 apart, and each of them has 24 pairs with distance 4 apart. o o o o | \|/ o o--o--o | | o--o------o------o--o o--o------o------o--o /|\ /|\ | | o o o o o o o o Lee Dickey Department of Pure Mathematics University of Waterloo ...!decvax!watmath!ljdickey