On Erdős sums of almost primes

Ofir Gorodetsky, Jared Duker Lichtman, Mo Dick Wong

In 1935, Erdős proved that the sums $f_k={\sum }_{n}1/(n\log n)$, over integers $n$ with exactly $k$ prime factors, are bounded by an absolute constant, and in 1993 Zhang proved that $…