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| n | a(n) |
|---|---|
| 6 | 1 |
| 7 | 6 |
| 8 | 27 |
| 9 | 104 |
| 10 | 369 |
| 11 | 1236 |
| 12 | 3989 |
| 13 | 12522 |
| 14 | 38535 |
| 15 | 116808 |
| 16 | 350064 |
| 17 | 1039896 |
| 18 | 3068145 |
| 19 | 9004182 |
| 20 | 26314773 |
| 21 | 76652582 |
| 22 | 222705603 |
| 23 | 645731148 |
| 24 | 1869303857 |
| 25 | 5404655358 |
| 26 | 15611296146 |
| 27 | 45060069406 |
| 28 | 129989169909 |
| 29 | 374843799786 |
| 30 | 1080624405287 |
[1,6,27,104,369,1236,3989,12522,38535,116808, 350064,1039896,3068145,9004182,26314773,76652582, 222705603,645731148,1869303857,5404655358, 15611296146,45060069406,129989169909,374843799786, 1080624405287] |