以此类推可得 0 L2L1A=00 3n 000 因为 32 2                =             = =                 = − − − − 1 ... 1 1 1 ... ... 1 ... 1 1 0 0 0 ... ... ... ... ... ... 0 0 ... 0 ... ... ... 2 3 2 1 2 1 1 2 1 1 ( ) (3) 3 (3) 3 3 (2) 2 (2) 2 3 (2) 2 2 (1) 1 (1) 1 3 (1) 1 2 (1) 1 1 1 2 2 1 n n n n n n n n n n l L l l l L U a a a a a a a a a a L L L L A 因为 以此类推可得