A Distributed Search Program for the 3x+1 Problem
				   
				  by
			   Gary T. Leavens
	Department of Computer Science, Iowa State University
		       Ames, IA, 50011-1040 USA


			       Abstract
This report describes the design of a distributed program that
searched for peaks in certain measures related to the 3x+1
problem. The searches for peaks in the number of steps taken, the
maximum value reached, and the number of steps before the values of
the iterates fall below the starting value exhibit a great deal of
parallelism, but there is also some small amount of synchronization
necessary. The design of a reliable and long-lived distributed system
that searched for such peaks is discussed from the partitioning of the
search to more detailed design issues such as ways to limit the
search. The search was implemented in the distributed programming
language Argus, and a few observations about Argus programming are
included. An appendix includes tables of various results from the
three years that the search program was running on six or more
computers.