[Velorivox]

How come prime numbers are special but squares aren’t? 4 and 9 both being squares seems to be a more striking commonality than your logic here…

[tarvaina]

Yeah. Alternative explanation: I'd say 3 and 7 are out because they often come up in fairy takes etc as magical. 5 is out because it's half of ten and the number of fingers. 2 is out because it is too small.