MAX PRIMARY KEY VALUE

Use @@Identity. See here[^].

Try this.

SELECT IDENT_CURRENT('tablename') + IDENT_INCR('tablename')

If you really need this than you will have to implement the functionality yourself.
After each insert into the table store the next auto number to be used, for this you can use the methods suggested in the other solutions.
Now when records are removed you can use your stored value to determine the next number to be used.
Please note that an auto number reset[^] might disturb this functionality.

But rethink why you need this functionality as it not very useful for an auto number.