The Serial number on a bill is suppose to be

Unique.However in 2013 the Bureau of

Engraving and Printing accidentally

Printed Duplicate Serial Numbers for some

Of the 2013 ⭐ Star Notes.

This run of Serial numbers were printed Twice

Once at the Fort Worth Printing Facility and

Once at the Washington D.C Printing Facility.

Which created Duplicates Star notes to be

Printed. Also an Automatic Printing "Error

Created by the United States Mints. It

Would hard to put a true Value on these

Errors.  Good Hunting.....