QUESTION :
What I am looking for is an “IF” formula that can solve my problem:

I have a single sheet with 2 columns and an unlimited number of rows.

On the first column (Column#1), I have a dropdown with only two values: “Option1” and “Option2”; “Option1” is linked to “x” and “Option2” is linked to “y”

On the second column (Column#2), I have to give consecutive numbers to each value.
I used this formula on Column#2 ~ =IF(A14=”Option1″,”x”,IF(A14=”Option2″,”y”,””)) ~ to offer the ID for each option.
I don’t know how to count the values that will have to appear after each value from Column#2.
e.g. – this is how it should look:
Column#1…………Column#2
 Option1…….x1
 Option1……..x2
 Option2…….y3
 Option1……..x4
 Option2…….y5
How can I do this?
ANSWER :
With data in column A, in B1 enterr:
=IF(RIGHT(A1,1)="1","X","Y") & ROW()
and copy down:
EDIT#1:
and to leave the formula cell blank of the column A cell is blank, use:
=IF(A1="","",IF(RIGHT(A1,1)="1","X","Y") & ROW())
EDIT#2:
To start anywhere, say B5, use
=IF(A5="","",IF(RIGHT(A5,1)="1","X","Y") & ROWS($1:1))