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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 16 |
| 3 | 1408 |
| 4 | 13568 |
| 5 | 606208 |
| 6 | 61878272 |
| 7 | 1956380672 |
| 8 | 21143027712 |
| 9 | 348742016303104 |
| 10 | 279852224852525056 |
| 11 | 5217315235815227392 |
| 12 | 118411884225053589504 |
| 13 | 842233813811702133686272 |
| 14 | 4096134057254358725165056 |
| 15 | 3447514330976633343761929207808 |
| 16 | 44711197753944482628093599547392 |
[1,4,16,1408,13568,606208,61878272,1956380672, 21143027712,348742016303104,279852224852525056, 5217315235815227392,118411884225053589504, 842233813811702133686272, 4096134057254358725165056, 3447514330976633343761929207808, 44711197753944482628093599547392] |