1 |
5 |
1 |
3 |
1 |
5 |
1 |
2×2?1 |
1 |
2×2+1 |
1 |
15 |
a3=
1 |
2×3?1 |
1 |
2×3+1 |
1 |
35 |
(2)觀察(1)的規(guī)律可得:a2008=
1 |
4015 |
1 |
4017 |
1 |
16128255 |
(3)找出一般形式為:an=
1 |
2 |
1 |
2n?1 |
1 |
2n+1 |
∴a1+a2+a3+a2008=
1 |
2 |
1 |
1 |
1 |
3 |
1 |
3 |
1 |
5 |
1 |
4017 |
1 |
2 |
4016 |
4017 |
2008 |
4017 |
1 |
3 |
1 |
5 |
1 |
3 |
1 |
5 |
1 |
2×2?1 |
1 |
2×2+1 |
1 |
15 |
1 |
2×3?1 |
1 |
2×3+1 |
1 |
35 |
1 |
4015 |
1 |
4017 |
1 |
16128255 |
1 |
2 |
1 |
2n?1 |
1 |
2n+1 |
1 |
2 |
1 |
1 |
1 |
3 |
1 |
3 |
1 |
5 |
1 |
4017 |
1 |
2 |
4016 |
4017 |
2008 |
4017 |