A simple FORTRAN program based primarily on the algorithm of Martin is
presented for enumerating isolated connected clusters of up to a given specified
number of particles on the square lattice. A brief explanation of the workings of
the program is also provided to facilitate its use by those interested in this
problem. To order 15, the program enumerates clusters at an average rate of
approximately 63,000/sec when implemented on an IBM 370/168 with the
extended optimizing compiler