The Riddle In The Middle

Whats next in this sequence:

1,2,3,4,5,6,7,...

No its not 8. Its 9.

See, the function that created this sequence is:

f(n) = n + floor(n/8)

Wisdom Of The Day:

"When something looks so easy,
suspicion would be the best first thing to do."

Any extra wisdoms you can think of?

A Riddle With A Wisdom

Two large jars of exact equal size. The first jar holds pepsi, the second jar holds the same but seven-up.

Using a small empty cup you remove a full small cup of pepsi and pour it in the sevenup jar, you mix the seven-up jar well. Then you remove from the seven-up jar (which has a small amount of pepsi in it) a full small cup and pour it into the pepsi jar.

The question now is:

Is there more pepsi in the sevenup jar than seven-up in the pepsi jar, or is it that there is more sevenup in the pepsi jar than pepsi in the sevenup jar?

This riddle simply proves that casual reasoning cant be trusted.