N.B. A detailed on-line essay by S. Finch was the starting point for this entry.
Let be a -Vector whose entries are each 1 (with probability ) or 0 (with probability ).
An -run is an isolated group of consecutive 1s. Ignoring the boundaries, the total number of runs satisfies
See also Percolation Theory, s-Cluster
Finch, S. ``Favorite Mathematical Constants.'' http://www.mathsoft.com/asolve/constant/rndprc/rndprc.html