We are given the following sequence:
[tex]1,8,15,22[/tex]
we notice that each term is obtained by adding 7 to the previous, like this;
[tex]\begin{gathered} a_1=1 \\ a_2=7+1=8 \\ a_3=7+7+1=7(2)+1=15 \\ a_4=7+7+7+1=7(3)+1=22 \end{gathered}[/tex]
Therefore, if a1 is the first term, a formula for the nth term is:
[tex]a_n=7(n-1)+a_1[/tex][tex]a_n=7(n-1)+1[/tex]
