Try this
=IF(ISBLANK(A$1),"",ROW()+A$1-1)


"bbc1" wrote:

I have 10 cells in column A
A1
A2
A3
A4
A5
etc
What I require is if cell A1 is blank then blank in all cells, if A1 is one
then add one to each cell
ie if A1 =1 A2 =2