$\,\left\{\begin{array}{rcr} 2020 \longrightarrow\,a_1\;& \\ 2024 \longrightarrow\,a_2\;& \\ 2028 \longrightarrow\,a_3\;& \\ 2032 \longrightarrow\,a_4\;& \\ ... \end{array} \right.\; \Longrightarrow$
Progressão aritmética
n = 50
r = 4
$\,a_n\,=\,a_1\,+\,(n\,-\,1)r\,$