x = least integer
x + 2 = middle integer
x + 4 = greatest integer
x + x + 2 - (x + 4) = 3030
2x + 2 - x - 4 = 3030
x - 2 = 3030
x = 3030 + 2
x = 3032 ← least integer
middle integer = x + 2 = 3034
greatest integer = x + 4 = 3032 + 4 = 3036
Check:
3032 + 3034 = 6066
3036 + 3030 = 6066
6066 = 6066