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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 60 |
| 2 | 3480 |
| 3 | 201780 |
| 4 | 11699760 |
| 5 | 678384300 |
| 6 | 39334589640 |
| 7 | 2280727814820 |
| 8 | 132242878669920 |
| 9 | 7667806235040540 |
| 10 | 444600518753681400 |
| 11 | 25779162281478480660 |
| 12 | 1494746811806998196880 |
| 13 | 86669535922524416938380 |
| 14 | 5025338336694609184229160 |
| 15 | 291382953992364808268352900 |
[1,60,3480,201780,11699760,678384300,39334589640, 2280727814820,132242878669920,7667806235040540, 444600518753681400,25779162281478480660, 1494746811806998196880,86669535922524416938380, 5025338336694609184229160, 291382953992364808268352900] |