| Abstrakt: |
Abstract: Let $\mathbb{Z}$ be the set of integers, $\mathbb{N}_0$ the set of nonnegative integers and $F(x_1,x_2)=u_1x_1+u_2x_2$ be a binary linear form whose coefficients $u_1$, $u_2$ are nonzero, relatively prime integers such that $u_1u_2\neq\pm1$ and $u_1u_2\neq-2$. Let $f\colon\mathbb{Z}\rightarrow\mathbb{N}_0\cup\{\infty\}$ be any function such that the set $f^{-1}(0)$ has asymptotic density zero. In 2007, M. B. Nathanson (2007) proved that there exists a set $A$ of integers such that $r_{A,F}(n)=f(n)$ for all integers $n$, where $r_{A,F}(n)=|\{(a,a') \colon n=u_1a+u_2a' \colon a,a'\in A\}|$. We add the structure of difference for the binary linear form $F(x_1,x_2)$. |
