The system that uses square roots was for generation 1-2 (which technecally had DV and Stat Exp rather than IV and EV, respectively). :P
It looks like you typed the formulas wrong, so I'll show you them proper. :P
Gen 1-2:
Anything surrounded by floor[] is rounded down. Anything surrounded by sqrt[] is square rooted. :P
HP= floor[(((Base+IV)*2+(floor[sqrt[EV]]/4)*Level/100]+Level+10
Other Stat= floor[(Base+IV)*2+(floor[sqrt[EV]]/4)*Level/100]+5
Gen 3+
Ditto above
HP= floor[(2*Base+IV+floor[EV/4])*Level/100]+Level+10
Other Stat= floor[(floor[(2*Base+IV+floor[EV/4])*Level/100]+5)*Nature
If the floor[]'s are too hard to follow, just remove them and round down whenever you divide and multiply by nature. :P
Conversly, replace sqrt[] with a radical. :P
Source
Hope I Helped!