Question

Which sequence can be generated from the formula f(x + 1) = (f(x))?

Answer 1

The formula f(x+1)=f(x) means that $a_n_+_1=a_n$

(remark $f(x)=a_x$)

we need a starting point so say 
$a_1=c$ and

$a_n_+_1=a_n$, to complete the recurrence relation.

This definition produces the constant sequence c, c, c, c, c, ....

answer:

$(a_n)=c$, where c is a constant