title: Number of ways n-1 edges may be chosen to form a connected graph with n nodes
body: <p>Basically, you require n-1 edges, to make a connected graph with n nodes. I would like to know if there is any theory behind finding the number of distinct ways you can select the n-1 edges, from the total n(n-1)/2 edges that are possible, such that the graph remains connected.</p>