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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 0 |
| 4 | 5 |
| 5 | 15 |
| 6 | 94 |
| 7 | 595 |
| 8 | 4458 |
| 9 | 37590 |
| 10 | 354051 |
| 11 | 3682646 |
| 12 | 41935695 |
| 13 | 518954293 |
| 14 | 6935360496 |
| 15 | 99553094537 |
| 16 | 1527716784020 |
| 17 | 24959724735564 |
| 18 | 432572721886437 |
| 19 | 7926615468800172 |
| 20 | 153129657663788761 |
| 21 | 3110514839038091643 |
| 22 | 66278515188844197218 |
| 23 | 1478222957082474301887 |
[0,0,1,0,5,15,94,595,4458,37590,354051,3682646, 41935695,518954293,6935360496,99553094537, 1527716784020,24959724735564,432572721886437, 7926615468800172,153129657663788761, 3110514839038091643,66278515188844197218, 1478222957082474301887] |