You are correct
for example f(1) = 3
and f(2) = f(2-1) - 2
= f(1) - 2
= 3 - 2 = 1
f(n) = f(n-1) - 2
f(1) = 3 eq1
f(2) = f(2-1) - 2
= f(1) - 2. put value from eq1 here
= 3 - 2
= 1
f(3) = f ( 3 - 1 ) - 2
= f(2) - 2
= 1 - 2
= -1
f(4) = f( 4 -1 ) - 2
= f( 3 ) - 2
= -1 - 2
= -3
3,1,-1,-3
