Find # put 1 then Skip rest

I am trying to find a formula as follows: Go down a column When you find a number put a 1 in the column to the right. Keep going down, if you find the same number skip it until you find a different number and put a 1 there. Keep going in that manner skipping any number you have already seen.

I have attached a sample file of what I'm trying to achieve. Once again thanks for all the help.........

Max