Calculate a specific number PHP
<p>I have a for loop, where $i is 0, and it will run until $i reaches 4. I am trying to make a code that would output numbers in an order like this: 01, 11, 02, 12, 03, 13... etc... Now, the thing is next: when $i is 1, the script should make an order of those number in the boundaries of 1 and 20. When $i is 2, it would be 21 to 40, etc.</p>

<p>I've tried many things (mostly deleted), could not come up with anything that would work the right way.</p>
