1、 1 1 an a1 1 an 1 3an 9 3 (1) a2 a3 (2) an 3 n n Sn. (1) an 1 3an 9 3 an 1 3an n 1 3 n 1 a2 3a1 9 a3 3a2 27 a2 12 a3 63. (2) an 1 3an 3 n 1 an 1 3 n 1 an 3 n 1 an 3 n 1 3 1 an 3 n n Sn n 3 n n 2 3n 2 n 6 . 2 ) an a1 1 d0 bn a2 b1 a6 b2 a18 b3. (1) an bn (2) cn n c1 b1 c2 b2 cn bn 1 2 a 2 n m 10 2 0
2、a1 1 an a1 d 1 an n b1 2 b2 6 b3 18 bn bn n 1 . (2) c1 b1 c2 b2 cn bn 1 2 n 2 n 1 c1 b1 1 2 c1 1 n c1 b1 cn 1 bn 1 cn bn 1 2 n 2 c1 b1 cn 1 bn 1 1 2 n 2 cn (2n n 1 2 n 1 cn (2n n 1 n N * cn (2n n 1 0 c1 1 c1 c2 10 c1 c2 c3 55 c1 c2 c3 c4 244 c1 c2 c3 c4 c5 973 c1 c2 c3 c4 c5 c6 3 646 m 4 5. 3 an n S
3、n a1 1 S3 6 bn b1 b2 b3 bn 2Sn. (1) an bn (2) nan n N * (1) a1 1 S3 6 3a1 3d 6 an d 1 an n. b1 b2 b3 bn 2Sn b1 b2 b3 bn 1 2Sn 1 n bn 2Sn Sn 1 2an 2 n (n b1 2S1 2 1 2 bn 2 n . (2) nan n 2 n cn n 2 n n cn 1 2 . 1 2 . 4 an a1 1 an 1 2an(n N * ) Sn n bn b1 a1 b4 S3. (1) an bn (2) cn 1 bn 2a2n 2 cn n Tn
4、1 3 Tn0 Tn Tn T1 1 3 . 1 3 Tn0 q 1 2 an 1 2 n 1 Sn 1 1 2 n 1 1 2 2 1 2 n 1 4 Sn Sn 2 2 2 1 2 n 1 2 n 2 t n 1 2 n t(n 2)1. n t(n 2)1 t 1 n 2 t 1 n 2 max 1. t (1 2 ) an an 0. (1) a2 a1 8 a3 m. m 48 an an m (2) a2k a2k 1 ak 1 (ak ak 1 a1) 8 k N * a2k 1 a2k 2 a3k an q q 0. (1) a2 a1 8 a3 m 48 a1q a1 8 a
5、1q 2 48 a1 16 8 3 q 3 3 a1 16 8 3 q 3 3. an an (16 8 3)(3 3) n 1 an (16 8 3)(3 3) n 1 . an a1 q a1q a1 8 a1q 2 m 8q 2 mq m 0 m 2 32m 0 m 32 m 0. a3 m 0 m 32 q 2. m 32 an an 2 n 2 . 5 (2) a2k a2k 1 ak 1 (ak ak 1 a1) 8 a1(q k 1)(q k 1 q k 2 1) 8 q 1. a2k 1 a2k 2 a3k a1q 2k (q k 1 q k 2 1) 8q 2k q k 1 8 q k 1 1 q k 1 2 q k 1 1 q k 1 q k 2 a2k 1 a2k 2 a3k 32.
