According to the given problem, the nth term of the sequence is given by,
[tex]\begin{gathered} a_n=3-7(n-1) \\ a_n=3-7n+7 \\ a_n=10-7n \end{gathered}[/tex]Substitute the values of n=0,1,2,3,....
[tex]\begin{gathered} a_0=10-7(0)=10-0=10 \\ a_1=10-7(1)=10-7=3 \\ a_2=10-7(2)=10-14=-4 \\ a_3=10-7(3)=10-21=-11 \end{gathered}[/tex]Thus, the sequence of obtained as,
[tex]10,3,-4,-11,\ldots\ldots\ldots,(10-7n)[/tex]So we can write,
[tex]\begin{gathered} a_1=3 \\ a_n=10-7n \end{gathered}[/tex]