Hey guys, I don't know what this is called so I'm just gonna describe it.

What I'm trying to achieve is this:

Let's say there's a list of variables:

a
a
a
a
b
b
b
c
c
d
d
e
f
f
g
g
g
g

What I want is to display, in a new column, this:

a
b
c
d
e
f
g

Is it possible? If so, how?

Thanks a lot in advance.