This looks like a geometric series, which is a series of the form
$$\sum_{n=0}^\infty a r^n$$
In your case $a = \frac{1}{2}$ and $r = \frac{1}{2}$.
This looks like a geometric series, which is a series of the form
$$\sum_{n=0}^\infty a r^n$$
In your case $a = \frac{1}{2}$ and $r = \frac{1}{2}$.