Respuesta :

[tex]\begin{gathered} a_n=7a_{n-1} \\ a_1=7 \\ a_2=7a_{2-1}=7a_1=7\cdot7=49 \\ a_3=7a_{3-1}=7a_2=7\cdot49=343 \\ a_4=7a_{4-1}=7a_3=7\cdot343=2401 \\ a_5=7a_{5-1}=7a_4=7\cdot2401=16807 \end{gathered}[/tex]