Benford's Law

In some large data set A, the frequencies at which each number appears follow the Benford's law. Recall the percentage of a digit appears out of all the digits ($0-9$) is given by: $$P(d)=\log(1+\frac{1}{d})$$

For example, if we want to know what percentage of the numbers appear were $2$, we plug in $d=2$. $$P(2)=\log(1+\frac{1}{2})=\log(\frac{3}{2})\approx 17.6\%$$