I don't know without some research. Meaning the Federal Reserve uses numbers for all the districts and each district is allotted certain 'blocks' of numbers and only a new series start at 1. But the FIRST of all numbers will be "A" 00000001, there will be another "00000001" when the "B" rolls around after A 99999999. Except certain blocks are reserved for UN-Cut currency. You see "Error" notes from mis-cuttings but many of these these are fake if you notice the serial numbers are from the UN-Cut block. Someone intentionally mis-cut these for profit (very illegal of caught). So are you totally confused yet? My point is you can't always tell. BUT any note with a LOT of zeros up front looks good to collectors. Now I know that is as clear as mud!! PLUS my memory of the details are not 100% accurate I am sure.