Unique sequential values

[CaptainGravyBum]

This will no doubt be an easy one for you guys, but I'm getting nowhere.
I have a countif formula for a column of order numbers to show when there are duplicate values, this works ok and return 2 if there are 2 duplicates, 3 for 3 duplicates and so on.
Ideally I need to make another column only return a result for one of the duplicate rows, so is there a way to make the countif formula return a 1 for the first instance of a duplicate and 2 for the second instance, so I can just ignore anything larger than 1?

 

[awoohaw]

assuming first order ID is in G3, try:

=if(Countif($G$3:$G$3000,G3)>=2,Countif($G$3:$G3,G3),"")

 

[CaptainGravyBum]

assuming first order ID is in G3, try:

=if(Countif($G$3:$G$3000,G3)>=2,Countif($G$3:$G3,G3),"")

Absolutely perfect! thanks @awoohaw

 

[awoohaw]

My pleasure, happy to help!