Banknote collectors have decided that certain uncommon sequences and patterns are "interesting". For example there are only 10,000 "radar" notes for any particular letter combination (out of a possible 100 million possibilities. This has three different numbers in no particular pattern or order, and undoubtedly quite a few more than 10,000. So in deciding if something is "interesting", you have to think of how many similar ones there are.
This is notwithstanding that every serial number is unique!
This is notwithstanding that every serial number is unique!





















