Erdős problem 470

Benkoski and Erdős [BeEr74](https://mathscinet.ams.org/mathscinet/relay-station?mr=347726) proved that the set of weird numbers has positive density.

HasPosDensity is the right reading here, rather than the positive *lower* density that Erdős' "positive density" usually abbreviates. Their Theorem 5 is stated as "the density of weird numbers is positive", and they first establish that the density exists at all: "It is clear that the weird numbers have a density since both the abundant numbers and the pseudoperfect numbers have a density. (A weird number is abundant and not pseudoperfect.)" The work in the paper goes into showing that density is not 0.