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| n | a(n) |
|---|---|
| 1 | 256 |
| 2 | 882 |
| 3 | 1792 |
| 4 | 8612 |
| 5 | 18176 |
| 6 | 114056 |
| 7 | 242176 |
| 8 | 1784720 |
| 9 | 3777536 |
| 10 | 30197792 |
| 11 | 63711232 |
| 12 | 528982592 |
| 13 | 1113952256 |
| 14 | 9408350336 |
| 15 | 19793944576 |
| 16 | 168456608000 |
| 17 | 354255650816 |
| 18 | 3025121034752 |
| 19 | 6360407375872 |
| 20 | 54395601462272 |
| 21 | 114358131163136 |
[256,882,1792,8612,18176,114056,242176,1784720, 3777536,30197792,63711232,528982592,1113952256, 9408350336,19793944576,168456608000,354255650816, 3025121034752,6360407375872,54395601462272, 114358131163136] |