A brief example would be, 507, 515, 523, 531, 549, 556, 564, 572, 580, 598, 606, 614, 622, 630, 648, 655.
The first digit (ones place) needs to go down by 2, 9 times, and then down once by 3. The second digit (tens place) needs to always go up by 1. The sum of the ones and tens place counts down, and skips one every 9 spots. Ex: 9,8,7,6,4,3,2,1,0,9,8,7,6,5,3,2,1,0,9,8,7,6,5,4,2,1,0,etc.
If you need any other info let me know. I am willing to pay for this via paypal.