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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 27 |
| 6 | 6715 |
| 7 | 196899 |
| 8 | 2547420 |
| 9 | 20372485 |
| 10 | 118262442 |
| 11 | 545477655 |
| 12 | 2114805415 |
| 13 | 7155153144 |
| 14 | 21689622270 |
| 15 | 60049653202 |
| 16 | 154055280120 |
| 17 | 370344275691 |
| 18 | 841651316923 |
| 19 | 1821128260530 |
| 20 | 3773553936582 |
[0,0,0,0,27,6715,196899,2547420,20372485, 118262442,545477655,2114805415,7155153144, 21689622270,60049653202,154055280120,370344275691, 841651316923,1821128260530,3773553936582] |