| 1 |
| 2 |
| 2 |
| 22 |
| 3 |
| 23 |
| 4 |
| 24 |
| n |
| 2n |
①×
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 22 |
| 2 |
| 23 |
| 3 |
| 24 |
| 4 |
| 25 |
| n |
| 2n+1 |
①-②得：
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 22 |
| 1 |
| 23 |
| 1 |
| 24 |
| 1 |
| 2n |
| n |
| 2n+1 |
| ||||
1−
|
| n |
| 2n+1 |
∴Sn=2-
| 1 |
| 2n−1 |
| n |
| 2n |
| 1 |
| 2 |
| 2 |
| 4 |
| 3 |
| 8 |
| n |
| 2n |
| 1 |
| 2 |
| 2 |
| 22 |
| 3 |
| 23 |
| 4 |
| 24 |
| n |
| 2n |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 22 |
| 2 |
| 23 |
| 3 |
| 24 |
| 4 |
| 25 |
| n |
| 2n+1 |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 22 |
| 1 |
| 23 |
| 1 |
| 24 |
| 1 |
| 2n |
| n |
| 2n+1 |
| ||||
1−
|
| n |
| 2n+1 |
| 1 |
| 2n−1 |
| n |
| 2n |