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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 30 |
| 4 | 498 |
| 5 | 11568 |
| 6 | 345432 |
| 7 | 12606240 |
| 8 | 543678672 |
| 9 | 27054328512 |
| 10 | 1525746223488 |
| 11 | 96167433279360 |
| 12 | 6699404849841408 |
| 13 | 511152613463843328 |
| 14 | 42391161255859802112 |
| 15 | 3796840836492517125120 |
| 16 | 365260399012767192102912 |
| 17 | 37561729737177160757133312 |
| 18 | 4111876748834828077514170368 |
[1,3,30,498,11568,345432,12606240,543678672, 27054328512,1525746223488,96167433279360, 6699404849841408,511152613463843328, 42391161255859802112,3796840836492517125120, 365260399012767192102912, 37561729737177160757133312, 4111876748834828077514170368] |