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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 49 |
| 6 | 169 |
| 7 | 603 |
| 8 | 2205 |
| 9 | 8217 |
| 10 | 31095 |
| 11 | 119185 |
| 12 | 461790 |
| 13 | 1805810 |
| 14 | 7117865 |
| 15 | 28250549 |
| 16 | 112806534 |
| 17 | 452862663 |
| 18 | 1826705940 |
| 19 | 7399893522 |
| 20 | 30092189864 |
| 21 | 122799412699 |
| 22 | 502709227763 |
| 23 | 2063939448400 |
| 24 | 8496355807149 |
| 25 | 35061664792175 |
[1,1,2,5,15,49,169,603,2205,8217,31095,119185, 461790,1805810,7117865,28250549,112806534, 452862663,1826705940,7399893522,30092189864, 122799412699,502709227763,2063939448400, 8496355807149,35061664792175] |