I have a list of Session names in column A (could be just 1 or more then 25). I would like a formula that looks a column A and if A1 is the same as A2 then put the number 1 in column B. This numbering would continue until the name in column A does not match the name below, when this occurs the numbering would start over at 1.

This formula would create ‘Position number in Session’ listing in column B.