Adding sets of integers to an array decreasing size of each set added by half

I have two arrays and I want to insert bits of the first array into the second

array1: {1,2,3,4,5,6}

array2: {-1,-1,-1,-1,-1,-1,-1}

My target is add half+1 of the numbers from the first array into the second array for the first iteration And then half of the remaining numbers for each further iteration: e.g.

1st iteration: {-1,-1,-1,1,2,3,4}

Second iteration: {-1,5,6,1,2,3,4}

the input data to be processed consists of exactly N positive integers, where N = 2^M − 2 and M = 3, 4, 5. That is, N = {6, 14, 30}.

I have the code that creates the first iteration: e.g.

for (int i1 = 0, i2 = Array2.length/2; i1 < ((Array2.length/2)+1) && i2 >=0 ;i1++, i2++) {
            Array2[i2] = Array1[i1];
        } 

However to generate the second iteration I am having a lot of trouble. If anyone can give me some advice on how to accomplish this I will really appreciate it!