3n−2n3^{n}-2^{n}3n−2n
3n+1−2n+13^{n+1}-2^{n+1}3n+1−2n+1
3n+2n3^{n}+2^{n}3n+2n
3n+1+2n+13^{n+1}+2^{n+1}3n+1+2n+1