not COUNTing if duplicate #s

[al]

How do I count entries in a column that duplicate? I want
to count repeating #s in a column as a single entry.
Thanks

 

[Peo Sjoblom]

Use a help column and something like

=A2=A1

then countif the TRUE in the help column.
If the numbers can be anywhere use the advanced filter to
extract a unique record (copy to another location, unique records only)
then use that unique liest and copy down (assume the original values are in
A2:A200 and the unique records
in C2:C150), in D2 put

=COUNTIF($A$2:$A$200,C2)

and copy down