I've made cluster bombs in one command! To activate, simply paste this into a command block, then activate. To detonate your cluster bombs, get a flint and steel, rename it "Cluster Detonator" (No quotations) and light up your tnt! When you light your cluster bomb, the first tnt will blow-up, then after ~2 seconds, three more tnts will span and blow-up! This will not continue spawning tnt untill your computer blue screens, and will only blow-up a maximum of four times. You can get to a pastebin of the command by clicking the link above. Hope you enjoy! :D