8 |
5 |
15 |
7 |
24 |
9 |
3 |
3 |
8 |
5 |
15 |
7 |
24 |
9 |
进而可得写成 −
(1+1)2−1 |
2×1+1 |
(2+1)2−1 |
2×2+1 |
(3+1)2−1 |
2×3+1 |
(4+1)2−1 |
2×4+1 |
故一个通项公式为:an=(−1)n
(n+1)2−1 |
2n+1 |
故答案为:an=(−1)n
(n+1)2−1 |
2n+1 |
8 |
5 |
15 |
7 |
24 |
9 |
8 |
5 |
15 |
7 |
24 |
9 |
3 |
3 |
8 |
5 |
15 |
7 |
24 |
9 |
(1+1)2−1 |
2×1+1 |
(2+1)2−1 |
2×2+1 |
(3+1)2−1 |
2×3+1 |
(4+1)2−1 |
2×4+1 |
(n+1)2−1 |
2n+1 |
(n+1)2−1 |
2n+1 |