Hi, Three more terms : 186622 = 1*8*6^6/2-2 186624 = 1*8*6^6*2/4 262149 = 2*6/2-1+4^9 Eric is right, I've avoided a^b^c because 1) it's ambiguous and 2) when you have something like 9^7^6^7, the machine doesn't like it very much :o) Have fun. Jean-Marc