More fun in 2015, Part 39
Number Theory
Level
3
\[\sum_{d|n}\mu\left(\frac{n}{d}\right)f(d)=n\]
If \(f(d)\) is an arithmetic function such that the equation above holds for all positive integers \(n\), find \(f(2015)\).
Notation: \(\mu\) denotes the Möbius function.
by
Otto Bretscher