Just for the record: In a previous post I gave the following link http://www.earlham.edu/~rodrimi/Periods%20of%20Fibonacci%20Sequences%20Mod%2... to a page with information about Fibonacci numbers mod n. (No authorship on that page.) I now see exactly the same web page at Kevin Brown's mathpages: http://www.mathpages.com/home/kmath078.htm Gary McGuire