random number generator without repetition

I am new to programing. I am making an application in VB.net. I want that on loading of a particular form, a random number will be generated as 1 or 2 or 3. When the form would be loaded 2nd time, a random number would be generated from 1, 2 or 3 but different than it is generated as earlier. And when form would be loaded 3rd time, a random number would be generated from 1, 2 or 3, but different than the previous 2 times, i.e. no repetition of the random numbers. For example if on first time form load, random number is 3, then second time it should be either 1 or 2. And if second time form load RN is 2, then third time form load it should be 1.

I will be thankful if someone could help me in writing this code in vb.net.