1 2 3 4 5 n =- 1 12 July 8, 2019 16 32 64 128 1 2 3 4 5 6 n =- 1 12 proof 1 2 3 4 5 6 n =- 1 12 demonstration 1 2 3 4 5 6 n =- 1 12 なぜ 1 2 3 4 5 n 1275 1 2 3 4 5 6 n =- 1 12 証明 1 2 3 4 5 6 n - 1 12证明
