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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 11 |
| 3 | 57 |
| 4 | 296 |
| 5 | 1537 |
| 6 | 7981 |
| 7 | 41442 |
| 8 | 215191 |
| 9 | 1117397 |
| 10 | 5802176 |
| 11 | 30128277 |
| 12 | 156443561 |
| 13 | 812346082 |
| 14 | 4218173971 |
| 15 | 21903215937 |
| 16 | 113734253656 |
| 17 | 590574484217 |
| 18 | 3066606674741 |
| 19 | 15923607857922 |
| 20 | 82684645964351 |
| 21 | 429346837679677 |
| 22 | 2229418834362736 |
| 23 | 11576441009493357 |
[1,2,11,57,296,1537,7981,41442,215191,1117397, 5802176,30128277,156443561,812346082,4218173971, 21903215937,113734253656,590574484217, 3066606674741,15923607857922,82684645964351, 429346837679677,2229418834362736, 11576441009493357] |