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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 2 |
| 3 | 1 |
| 4 | 10 |
| 5 | 14 |
| 6 | 75 |
| 7 | 178 |
| 8 | 738 |
| 9 | 2304 |
| 10 | 8753 |
| 11 | 31186 |
| 12 | 117244 |
| 13 | 444107 |
| 14 | 1698959 |
| 15 | 6637212 |
| 16 | 25978768 |
| 17 | 103470800 |
| 18 | 413378548 |
| 19 | 1671251159 |
| 20 | 6788681873 |
| 21 | 27799009080 |
| 22 | 114434701571 |
| 23 | 473862635406 |
| 24 | 1972068523477 |
| 25 | 8246133103745 |
| 26 | 34634859230481 |
| 27 | 146059305983882 |
| 28 | 618344086849853 |
| 29 | 2627035342133955 |
[1,0,2,1,10,14,75,178,738,2304,8753,31186,117244, 444107,1698959,6637212,25978768,103470800, 413378548,1671251159,6788681873,27799009080, 114434701571,473862635406,1972068523477, 8246133103745,34634859230481,146059305983882, 618344086849853,2627035342133955] |