If #f(1) = 3# and #f(n) = -2f(n-1) + 1#, what is #f(5)#?
#f(1)=3#
#f(n)=-2f(n-1)+1#
#f(2)=-2f(1)+1#
#f(2)=-2(3)+1=-6+2=-5#
#f(3)=-2f(2)+1#
#f(3)=-2(-5)+1#
#f(3)=11#
#f(4)=-2(f(3))+1#
#f(4)=-2(11)+1#
#f(4)=-22+1=-21#
#f(5)=-2(f(4))+1#
#f(5)=-2(-21)+1#
#f(5)=42+1#
#f(5)=43#