In order to calculate the first four terms of this sequence, let's use the values of n = 1, 2, 3 and 4 in the expression for An:
[tex]\begin{gathered} n=1\colon \\ A_1=42-7(1-1)=42 \\ \\ n=2\colon \\ A_2=42-7(2-1)=35 \\ \\ n=3\colon \\ A_3=42-7(3-1)=28 \\ \\ n=4\colon \\ A_4=42-7(4-1)=21 \end{gathered}[/tex]Therefore the first four terms are 42, 35, 28 and 21.
