30dbd869f32fbba193ad287ea4974cdb6d09965b
For example, \(S\left(3,2\right)\)\(=3\), because there are three ways to
partition three objects, namely \(a,b\) and \(c\) into two groups. \(\left(a\right)\left(bc\right),\left(b\right)\left(ac\right)\) and \(\left(c\right)\left(ab\right).\)