Respuesta :

hum, multiply by 3? nope
hmmm, add 26? yep

the sequence is
[tex]a_n=a_{n-1}+26[/tex]  when [tex]a_1=13[/tex]
or
[tex]a_n=13+26(n-1)[/tex] or [tex]a_n=26n-13[/tex]