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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 15 |
| 2 | 176 |
| 3 | 1856 |
| 4 | 18432 |
| 5 | 176128 |
| 6 | 1638400 |
| 7 | 14942208 |
| 8 | 134217728 |
| 9 | 1191182336 |
| 10 | 10468982784 |
| 11 | 91268055040 |
| 12 | 790273982464 |
| 13 | 6803228196864 |
| 14 | 58274116272128 |
| 15 | 496979255754752 |
| 16 | 4222124650659840 |
| 17 | 35747322042253312 |
| 18 | 301741175033823232 |
[1,15,176,1856,18432,176128,1638400,14942208, 134217728,1191182336,10468982784,91268055040, 790273982464,6803228196864,58274116272128, 496979255754752,4222124650659840, 35747322042253312,301741175033823232] |