Can you make the number 18 using only 8 4 2 and 1?

Answer 1

You can make every number up to 15 using only 8, 4, 2, and 1 .

If you want to expand your horizons all the way to 18, you'll need the next one
in the same series. That's 16. Once you have that, you'll be able to make every
number up to 31 .