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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 12 |
| 3 | 152 |
| 4 | 2960 |
| 5 | 78112 |
| 6 | 2607808 |
| 7 | 105432448 |
| 8 | 5008584960 |
| 9 | 273482293760 |
| 10 | 16878251101184 |
| 11 | 1161918967060480 |
| 12 | 88277165100666880 |
| 13 | 7337286679766179840 |
| 14 | 662287143981044121600 |
| 15 | 64516370031367063175168 |
| 16 | 6746443728505612426870784 |
| 17 | 753763691778003738319519744 |
[1,2,12,152,2960,78112,2607808,105432448, 5008584960,273482293760,16878251101184, 1161918967060480,88277165100666880, 7337286679766179840,662287143981044121600, 64516370031367063175168,6746443728505612426870784, 753763691778003738319519744] |