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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 12 |
| 3 | 128 |
| 4 | 1968 |
| 5 | 39488 |
| 6 | 977088 |
| 7 | 28742912 |
| 8 | 979744512 |
| 9 | 37968868352 |
| 10 | 1648597834752 |
| 11 | 79272057049088 |
| 12 | 4181485522464768 |
| 13 | 240067201819885568 |
| 14 | 14902137637759008768 |
| 15 | 994529776192394166272 |
| 16 | 71009035425186633940992 |
| 17 | 5401058272888913168433152 |
| 18 | 435991257271370763778916352 |
[1,2,12,128,1968,39488,977088,28742912,979744512, 37968868352,1648597834752,79272057049088, 4181485522464768,240067201819885568, 14902137637759008768,994529776192394166272, 71009035425186633940992,5401058272888913168433152, 435991257271370763778916352] |