# Practical Formula

**Algebra**Level pending

Hi, anyone, help me out:

Find the general formula for the series=> 1, 2, 4, 6, 8, 12, 16, 18, 20, 24, 28, 30, 32, 36, 40, 42, 48, 60.............

HINT: We can express each number starting from 1 to the particular number by the sum of the distinct factors of that number, for example, suppose the number is 8. Now, the factors are: 1,2,4,8. now see, it is possible to make every number between 1 and 8 as..... 1, 2, 3(1+2), 4, 5(1+4), 6(2+4), 7(1+2+4), 8. Such numbers are known as PRACTICAL numbers. The answer given is just this number. I want the general formula.