If is the number of ways in which five different employees can sit into four indistinguishable offices where any office may have any number of persons including zero, then is equal to [2024]
(4)
Number of ways in which five different employees can sit are
5 0 0 0 5!/5! = 1
4 1 0 0 5!/4! = 5
3 2 0 0 5!/3!2! = 10
3 1 1 0 5!/3! 1! 1! 2! = 10
2 2 1 0
2 1 1 1
Total number of ways =1 + 5 + 10 + 10 + 15 + 10 = 51