Krenko doubles your Goblins, then Skirk Prospector sacrifices Krenko and enough Goblins to recast it, tax included, for less with Goblin Warchief. With Goblins minus tax at 4 the loop makes two more Goblins each time, as fast as the tax grows; above that it grows faster and faster, below it dies out.
Goblins needed6with commander tax
The loop grows every timeArbitrarily many Goblins, two more each loop, as the tax grows by .
6 of 6 Goblins
Goblins, step by step
10010203040
To start: 6 GoblinsTo start: 6 Goblins0
Krenko taps: 12 GoblinsKrenko taps: 12 Goblins1
Sacrifice 5, Krenko included, to recast it for : 8 GoblinsSacrifice 5, Krenko included, to recast it for : 8 Goblins2
Krenko taps: 16 GoblinsKrenko taps: 16 Goblins3
Sacrifice 7, Krenko included, to recast it for : 10 GoblinsSacrifice 7, Krenko included, to recast it for : 10 Goblins4
Krenko taps: 20 GoblinsKrenko taps: 20 Goblins5
Sacrifice 9, Krenko included, to recast it for : 12 GoblinsSacrifice 9, Krenko included, to recast it for : 12 Goblins6
Krenko taps: 24 GoblinsKrenko taps: 24 Goblins7
Sacrifice 11, Krenko included, to recast it for : 14 GoblinsSacrifice 11, Krenko included, to recast it for : 14 Goblins8
Krenko taps: 28 GoblinsKrenko taps: 28 Goblins9
Sacrifice 13, Krenko included, to recast it for : 16 GoblinsSacrifice 13, Krenko included, to recast it for : 16 Goblins10
Krenko taps: 32 GoblinsKrenko taps: 32 Goblins11
Sacrifice 15, Krenko included, to recast it for : 18 GoblinsSacrifice 15, Krenko included, to recast it for : 18 Goblins12
Krenko taps: 36 GoblinsKrenko taps: 36 Goblins13
Sacrifice 17, Krenko included, to recast it for : 20 GoblinsSacrifice 17, Krenko included, to recast it for : 20 Goblins14
Krenko taps: 40 GoblinsKrenko taps: 40 Goblins15
Sacrifice 19, Krenko included, to recast it for : 22 GoblinsSacrifice 19, Krenko included, to recast it for : 22 Goblins16