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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 17 |
| 6 | 51 |
| 7 | 199 |
| 8 | 653 |
| 9 | 2746 |
| 10 | 9506 |
| 11 | 41887 |
| 12 | 150209 |
| 13 | 683534 |
| 14 | 2513812 |
| 15 | 11714529 |
| 16 | 43913589 |
| 17 | 208460660 |
| 18 | 793362271 |
| 19 | 3822998161 |
| 20 | 14731492719 |
| 21 | 71883765642 |
| 22 | 279923388563 |
| 23 | 1380780426067 |
| 24 | 5426284435421 |
| 25 | 27023956574169 |
| 26 | 107069182011993 |
| 27 | 537876237669664 |
[1,1,1,2,5,17,51,199,653,2746,9506,41887,150209, 683534,2513812,11714529,43913589,208460660, 793362271,3822998161,14731492719,71883765642, 279923388563,1380780426067,5426284435421, 27023956574169,107069182011993,537876237669664] |