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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 9 |
| 4 | 38 |
| 5 | 176 |
| 6 | 832 |
| 7 | 4039 |
| 8 | 19938 |
| 9 | 99861 |
| 10 | 506042 |
| 11 | 2590099 |
| 12 | 13370898 |
| 13 | 69540016 |
| 14 | 364028992 |
| 15 | 1916585714 |
| 16 | 10142059868 |
| 17 | 53911982971 |
| 18 | 287736310102 |
| 19 | 1541243386819 |
| 20 | 8282387269058 |
| 21 | 44638363790176 |
| 22 | 241216694913632 |
| 23 | 1306608966475854 |
| 24 | 7092980525443588 |
| 25 | 38581011402034156 |
[1,2,9,38,176,832,4039,19938,99861,506042,2590099, 13370898,69540016,364028992,1916585714, 10142059868,53911982971,287736310102, 1541243386819,8282387269058,44638363790176, 241216694913632,1306608966475854,7092980525443588, 38581011402034156] |