Answer :
[tex]f(0)=261[/tex][tex]f(1)=261-1(5)[/tex][tex]f(2)=261-2(5)[/tex]
then, for all n greater or equal than 1
[tex]f(n)=261-5n[/tex]then the 50th term is f(49)= 261-5(49)= 16, then the final answer is 16.