so it is looking for ab+a+b, if you add one to that, they will still be the same, distinct or not distinct, so it wont change it so you can just make it ab+a+b+1, which factors as (a+1)(b+1). now you are just trying to find those values.
a,b=2,4,6,8,10,12,14
i found no way to do this other than casework..
if a = 2 then it equals 9,15,21,27,33,39, and 45
if a = 4 then it equals 15,25,35,45,55,65, and 75
if a = 6 then it equals 21,35,49,63,77,91, and 105
if a = 8 then it equals 27,45,63,81,99,117, and 135
if a = 10 then it equals 33,55,77,99,121,143, and 165
if a = 12 then it equals 39,65,91,117,143,169, and 195
if a = 14 then it equals 45,75,105,135,165,195, and 225
counting them, and listing, you get the numbers 9, 15, 21, 27, 33, 39, 45, 25, 35, 55, 65, 75, 49, 63, 77, 91, 105, 81, 99, 117, 135, 121, 143, 165, 169, 195, and 225, for a total of 27 numbers.
HOPE THIS HELPED!!
(may be 28, im not sure)
