Given a set $P$ of real numbers $\ge 1$, define the gap among different products in $P$ as
$$g(P) = \inf \big\{\prod_{i=1}^n p_i^{a_i} - \prod_{i=1}^n p_i^{b_i} \mid p_i\in P;\,\, p_i\ne p_j \,\text{ if }\, i\ne j ; \,\,a_i, b_i \in \mathbb{N}\cup \{0\};\,\, a_1 \ne b_1 \big\}$$
If $g(P)>0$ in one could say that the set of products of members of $P$ has unique factorization in an essentially strong way.
The main question is: can any infinite sets $P$ with $g(P)> 0$ be produced with a density similar to that of the primes, but more regularly distributed (for example $p_i=(i+a)\log(bi+c)+d$ for some constants $a,b,c,d$, or $iH_i+a$)?
Can any interesting set $P$ with $g(P)>0$ be produced at all?
