The values are increasing equally so it's a linear function.
The formula is [tex]y=mx+b[/tex]
For [tex]x=0[/tex], [tex]y=1[/tex] so [tex]b=1[/tex] (y-intercept).
Take some point and put its coordinates into the equation to find [tex]m[/tex] (slope).
[tex]2=m\cdot2+1\\
2m=1\\
m=\dfrac{1}{2}\\\\
\boxed{y=\dfrac{1}{2}x+1}[/tex]
