I understand that LCM is a multiplicative function. So, for the case where n = 6, it should be like f(6) = f(2) * f(3), f(2) = (1 + 2) + (2 + 2) = 7, f(3) = (1 + 3) + (3 + 3) = 10, therefore f(6) = f(2) * f(3) = 7 * 10 = 70. But this is the wrong answer. Someone please help me out to figure out the right solution. Any help is really appreciated.