Problem 950

Erdős Problem #950: declared status 'open'. Formalized: no. Let$$f(n) = \sum_{p<n}\frac{1}{n-p}.$$Is it true that$$\liminf f(n)=1$$and$$\limsup f(n)=\infty?$$Is it true that $f(n)=o(\log\log n)$ for all $n$? Prize: no. Tags: number theory, primes.