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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 1 |
| 8 | 18 |
| 9 | 261 |
| 10 | 3420 |
| 11 | 42300 |
| 12 | 504000 |
| 13 | 5850000 |
| 14 | 66600000 |
| 15 | 746999991 |
| 16 | 8279999757 |
| 17 | 90899995383 |
| 18 | 989999925399 |
| 19 | 10709998904070 |
| 20 | 115199984885400 |
| 21 | 1232999800740000 |
| 22 | 13139997460650000 |
| 23 | 139499968482900081 |
| 24 | 1475999617032002916 |
| 25 | 15569995426740068526 |
[0,0,0,0,0,0,0,1,18,261,3420,42300,504000,5850000, 66600000,746999991,8279999757,90899995383, 989999925399,10709998904070,115199984885400, 1232999800740000,13139997460650000, 139499968482900081,1475999617032002916, 15569995426740068526] |