The Lucky Penny - S1.E16

Ned's father opened a new bank account for Ned, after finding all the change around Ned's room. To Ned's horror, however, that means he has deposited his "lucky penny", a treasured penny that has an image of Gene Hackman as Lex Luthor on it. When the bank refuses to get it for him, Newton helps Ned by breaking into the bank vault to find it. They do, but Newton had to give away $3.5 million in the bank vault to make it easier to find. They're saved, however, when a passing coin collector points out that Ned's penny is only one of two in the entire world, worth $3.5 million. Ned and Newton quickly put all the money back in the vault, and the bank owner gives Ned the only other Gene Hackman penny in existence.