hello everyone. tonight I found an interesting serial number on a $20 1996 series bill a customer used. I'm still new to serial numbers so I was just wondering what you guys thought of it and if its considered collectible. well, if it was in perfect shape. it has a few folds in it otherwise its crisp but I know the folds kill any premium anyway. I'm more interested on what you guys think of the serial number. it 71757571 it got my attention because its 71,75,75,71 if you break it into 2 number chunks. thanks for the help guys! I appreciate it.