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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 28 |
| 5 | 730 |
| 6 | 20460 |
| 7 | 633619 |
| 8 | 21740040 |
| 9 | 823020596 |
| 10 | 34174098440 |
| 11 | 1546855384261 |
| 12 | 75883563554436 |
| 13 | 4013184755214414 |
| 14 | 227719025845257492 |
| 15 | 13804358188086757719 |
| 16 | 890571834923460488784 |
| 17 | 60933371174617735181160 |
| 18 | 4407783770975985847999440 |
| 19 | 336154167664942342604334345 |
[0,0,0,1,28,730,20460,633619,21740040,823020596, 34174098440,1546855384261,75883563554436, 4013184755214414,227719025845257492, 13804358188086757719,890571834923460488784, 60933371174617735181160,4407783770975985847999440, 336154167664942342604334345] |