Erdős problem 830

We say that $a,b\in \mathbb{N}$ are an amicable pair if $\sigma(a)=\sigma(b)=a+b$. If $A(x)$ counts the number of amicable $1\leq a\leq b\leq x$ then one can show that $A(x) \leq x \exp(-(\tfrac{1}{2}+o(1))(\log x\log\log x)^{1/2})$.