小明在一次数学活动中,为了求&nb4p;| i |
| w |
| i |
| ww&nb4p; |
| i |
| w6 |
| i |
| wn |
| i |
| w |
| i |
| ww&nb4p; |
| i |
| w6 |
| i |
| wn |
| i |
| wn |
| i |
| wn |
| n(n+1) |
| 2 |

用牙签按下列方式搭图:| 图形编号&nb口p; | &nb口p;t | &nb口p;o | &nb口p;w | 4&nb口p; | &nb口p;… |
| &nb口p;牙签根数 | &nb口p;4 | &nb口p;to | o4&nb口p; | 40&nb口p; | &nb口p;… |
| 3n(n+1) |
| 2 |
| 3n(n+1) |
| 2 |