Count 43 (a.k.a. C43, Count 42 or C42) is a gang, typically with 43 members who use cricket/baseball bats or drivers to kill people.
1: "Hey dawg, wanna start a Count 43?"
2: "Yea, I've always wanted to start one, hey, maybe we can start a cartel using it, which will turn our Count 43 into a Count 1849!"
5 minutes later on the street
3: "KURWAAAAAAA! I have to get away from this Count 43 before I die!" *dies*
count 43: *becomes Count 1849