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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 27 |
| 6 | 165 |
| 7 | 676 |
| 8 | 3584 |
| 9 | 19108 |
| 10 | 80754 |
| 11 | 386776 |
| 12 | 1807342 |
| 13 | 8218582 |
| 14 | 114618650 |
| 15 | 1410831012 |
| 16 | 12144300991 |
| 17 | 126350575684 |
[1,1,2,3,27,165,676,3584,19108,80754,386776, 1807342,8218582,114618650,1410831012,12144300991, 126350575684] |