Thanks a lot.

Just a clarification, the + 1 in my formula was the + 1 you thought I didn't have, I should have written:

x + x-1 + x-2 + x-3 + ... + x-x + 1

Thanks for pointing out the x·(x+1)/2 simplification. It seems to be high time I start reviewing some math before I forget everything. I have your site bookmarked and have the best intentions of reading and understanding previous postings.

Thanks again for your time,

Paul.