Shell-sort algorithm variations in Java

Question

Is there a way to calculate the starting point of a for loop and the adjustments to it. The original loop has these conditions

for( int gap = a.length / 2; g

Answer 1

for( int gap = 1; gap < ((a.length + 2)/3); gap = (((((gap *2)+1)*3)-1)/2))

Answer 2

The "k" value is the element of the sequence. So your for loop would probably look something like:

    for (int k = 0; (Math.pow(3, k) - 1) / 2 <= Math.ceil(n / 3); k++) {
        int gap = (int) ((Math.pow(3, k) - 1) / 2);
        ...
    }