If you have a helium filled balloon in a closed car, and you go around corner.
Will the balloon swing into or out of the corner?
Hint: Does it matter that helium is lighter than air?
Answer: Into the corner.
As the car goes into the corner everything will be forced to one side, the outside of the corner. However, as helium is lighter than air, the air will go into the outside of the corner pushing the balloon the opposite way.
There are two alternate series, starting with the first two numbers, and each formed by doubling the preceding number in its own series and subtracting 2.