Question 39860
Well one way to get the answer is to merely lay out all the possibilties...
1st 2nd 3rd registers
4,0,0
3,1,0
3,0,1
2,2,0
2,1,1
2,0,2
1,3,0
1,2,1
1,1,2
1,0,3
0,4,0
0,3,1
0,2,2
0,1,3
0,0,4
I think that covers them all...so how many is that?