Extract unique value from column of consecutive repeated values

Hi,

I have a column of numbers, some of which are repeated consecutively, and I want to extract a single value for each of these instances. Eg the column could look like:

2
2
6
4
4
4
12
12
2
2
2
5
5
4
4
15
15
etc


I want to 'collapse' each consecutive repeated value into just a single value. I.e. like this:
2
6
4
12
2
5
4
15
etc

So, it's not just a simple case of extracting unique values - since the non-consecutive repeats (eg 2,4) would not be preserved.

Any suggestions?

Thanks,

Thanks a lot - that worked well.

Another way ...

=IFERROR(INDEX(A:A,AGGREGATE(15,6,ROW($A$1:$A$17)/($A$1:$A$17<>$A$2:$A$18),ROWS($A$1:A1))),"")

Thanks - that works too.