Vibe96 is the closest. The correct answer was Horses improved with a Pasture
Here's the breakdown for clues:
#1: 41 = +2, 2 = +3 - This refers to the base production yield of the pasture. For 41 civs it's 2 production, but for Russia and the Huns it's 3.
#2: +1 = +2; +1 = +1 - This one refers to two things: the first refers to building a Circus in a city with a nearby improved source of Horses, which yields +2 Happiness, while the second part refers to the fact that the Fertilizer technology adds +1 food to Pastures.
#3: 42: +1 = +1. 1: +1 = +1, +1. - This refers to the fact that, for 42 Civs, building a Stable adds +1 Production to all pastures, but for one (Poland), the Ducal Stable yields +1 food and +1 Gold.
If s = Standard, then x = 2 or 4 - As vibe96 noted, this is simply the fact that if the resource setting is Standard, then the amount of Horses in a "deposit" is either 2 or 4.