I'm in dire need of help

I have a column of 2500 entries that account for no more than 10 duplicates.

So I know there has to be at least 250 unique entries. I'd like to
account for every item but I don't want to have the duplicates listed.

So Column A might look like this:

a
a
a
a
a
a
b
b
c
c
c
c
d
d
d

I'd ultimately want col a to just have

a
b
c
d

and then col b have how many times that instance showed up

a - 6
b - 2

etc
etc