Infinite number of bodies, each of mass $2\text{kg}$ are situated on the x-axis at distances $1\text{m},2\text{m},4\text{m},8\text{m},\dots$, respectively, from the origin. The resulting gravitational potential due to this system at the origin will be:

Gravitational potential $V$ at the origin is the sum of potentials due to all individual masses:
$$V=-\frac{G{m}_1}{r_1}-\frac{G{m}_2}{r_2}-\frac{G{m}_3}{r_3}-\dots$$
Given $m=2\text{kg}$ for all bodies:
$$V=-G(2)\left[\frac{1}{1}+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\dots \infty \right]$$
The terms in the bracket form a Geometric Progression (GP) with first term $a=1$ and common ratio $r=\frac{1}{2}$.Sum of infinite GP $S_{\infty }=\frac{a}{1-r}$:
$$S_{\infty }=\frac{1}{1-1/2}=\frac{1}{1/2}=2$$
Substituting back:
$$V=-2G\times 2=-4G$$