24301

I have found out that all multiples of 3 ,except from one, can be made by three consecutive numbers. The one exception to this is 3 as it cannot be made by three consecutive numbers. I have also worked out that the theory can be proved by using algebra. If the multiple of three is represented as x then:
x=(x/3-1)+(x/3)+(x/3+1)
For example:
18=5+6+7
21=6+7+8
24=7+8+9