Each element of S ( 4 , 3 ) can be thought of as a multiset of cardinality n = 4 ; the elements of such multiset are taken from the set { 1 , 2 , 3 } of cardinality g = 3 , and the number of such multisets is the multiset coefficient ⟨ 3 4 ⟩ = ( 3 + 4 − − 1 3 − − 1 ) = ( 3 + 4 − − 1 4 ) = 6 ! 4 ! 2 ! = 15