Centaur Publications published Amazing-Man Comics, created by Bill Everett and Lloyd Jacquet, in September 1939. This comic featured the adventures of John Aman alias Amazing Man.
Amazing-Man Comics ran from issue #5 to #26, ending the series in February 1942.
Amazing-Man Comics #5 was the first issue of this comic. The reason Centaur started at issue 5 was to create the illusion that the character had been around for a few months. People had become reluctant to buy a first issue back in the golden age of comics because there was a good chance the character in the first issue would never be seen again.