Please explain the following recursion question step by step.

public static void main(String[] args) { writeSquares(8); } public static void writeSquares(int n) { if (n < 1) { throw new IllegalArgumentException(); } if (n == 1) { System.out.print(1); } else { if (n % 2 == 1) { System.out.print(n * n + ", "); writeSquares(n - 1); } else { writeSquares(n - 1); System.out.print(", " + n * n); } } } }