You could have just posted the formula which is 40*lvl.
Paladin gets 50*lvl (100-1500), someone please post what a warrior gets so I don't have to bother playing a warrior to lvl 2
If I had to guess I'd say a warrior gets 60*lvl.
Also, have you noticed that you only get to raise leadership on even levels unless you skip it in favor of a stat in which case you will be offered leadership on the next level and every two levels from that point on. So to max it out, you should probably start getting leadership on level 14 or 16.