- #1

Thecla

- 132

- 10

- TL;DR Summary
- The sum of an harmonic series without numbers containing a nine is finite

The sum of the harmonic series(1/1+1/2+1/3...) is infinite. However, if you exclude all the terms that contain the number nine, the sum is just under 23.

From 1 to 100 19% of the terms are excluded

From 1 to 1000 27.1% of the terms are excluded

Is there a formula for a N digit number what the percentage of numbers from 1 to N that contain a 9?

From 1 to 100 19% of the terms are excluded

From 1 to 1000 27.1% of the terms are excluded

Is there a formula for a N digit number what the percentage of numbers from 1 to N that contain a 9?