N 3 3n 2 3n 1 July 8, 2019 16 32 64 128 N 3 3n 2 2n 120 N 3 3n 2 2n 120 0 N 3 3n 2 4n 1 chia hết cho 6 N 3n 1 3n 2 3 is divisible by 9 N 3 n
