\( \frac2^n+3 \cdot (2^2)^n-1(2^3)^n-2 = \frac2^n+3 \cdot 2^2n-22^3n-6 = \frac2^n+3 + 2n - 22^3n - 6 = \frac2^3n + 12^3n - 6 = 2^(3n + 1) - (3n - 6) = 2^7 = 128 \). - go-checkin.com