There are 166 pairs that begin like this (a, b): (497, 2) , (494, 4) , (491, 6) , (488, 8) , (485, 10) , (482, 12) ....etc.
Notice that as "a" DECREASES by 3, "b" INCREASES by 2. This pattern holds for 166 pairs, the last one being:
a = 2 and b =332.
