Find missing serial numbers
I discovered today that there are invoice numbers missing in our accounting DB. The number is set to auto-enter Serial, Unique. Looking back over the past 6 months I manually found 6 numbers missing. Only 2 people have access to the system and both of us are sure nothing has been deleted. Is there a simple formula to search for theses numbers? There are c. 4,000 records, manual seach would be laborious.