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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 9 |
| 5 | 15 |
| 6 | 75 |
| 7 | 133 |
| 8 | 676 |
| 9 | 1712 |
| 10 | 7295 |
| 11 | 16797 |
| 12 | 100889 |
| 13 | 208013 |
| 14 | 1083061 |
| 15 | 3186268 |
| 16 | 14634359 |
| 17 | 35357671 |
| 18 | 209715154 |
| 19 | 477638701 |
| 20 | 2679305455 |
| 21 | 7638371497 |
| 22 | 35224117709 |
| 23 | 91482563641 |
| 24 | 568102780247 |
| 25 | 1311836293464 |
| 26 | 6979729709485 |
| 27 | 21256008509080 |
| 28 | 103440124113965 |
[1,1,2,3,9,15,75,133,676,1712,7295,16797,100889, 208013,1083061,3186268,14634359,35357671, 209715154,477638701,2679305455,7638371497, 35224117709,91482563641,568102780247, 1311836293464,6979729709485,21256008509080, 103440124113965] |