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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 4 |
| 4 | 4 |
| 5 | 10 |
| 6 | 35 |
| 7 | 10 |
| 8 | 20 |
| 9 | 165 |
| 10 | 165 |
| 11 | 20 |
| 12 | 35 |
| 13 | 560 |
| 14 | 1330 |
| 15 | 560 |
| 16 | 35 |
| 17 | 56 |
| 18 | 1540 |
| 19 | 7140 |
| 20 | 7140 |
| 21 | 1540 |
| 22 | 56 |
| 23 | 84 |
| 24 | 3654 |
| 25 | 29260 |
| 26 | 57155 |
| 27 | 29260 |
| 28 | 3654 |
| 29 | 84 |
| 30 | 120 |
| 31 | 7770 |
| 32 | 98770 |
| 33 | 333375 |
| 34 | 333375 |
| 35 | 98770 |
| 36 | 7770 |
| 37 | 120 |
| 38 | 165 |
| 39 | 15180 |
| 40 | 287980 |
| 41 | 1543465 |
| 42 | 2667126 |
| 43 | 1543465 |
| 44 | 287980 |
| 45 | 15180 |
| 46 | 165 |
[1,4,4,10,35,10,20,165,165,20,35,560,1330,560,35, 56,1540,7140,7140,1540,56,84,3654,29260,57155, 29260,3654,84,120,7770,98770,333375,333375,98770, 7770,120,165,15180,287980,1543465,2667126,1543465, 287980,15180,165] |