A fencepost loop is a common algorithmic pattern where you want to perform N tasks with N-1 things between them. It's like a fence with N posts with N-1 wires between the posts.
To achieve this, place one "post" outside your loop, then alternate between "wires" and "posts" inside the loop.
Example:
System.out.print(1); // |==|==|==|==| fence for (int i = 2; i <= 5; i++) { System.out.print(".." + i); // 1..2..3..4..5 }