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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 28 |
| 3 | 1112 |
| 4 | 87568 |
| 5 | 11447072 |
| 6 | 2239273408 |
| 7 | 612359887232 |
| 8 | 223061763490048 |
| 9 | 104399900177326592 |
| 10 | 61049165415292607488 |
| 11 | 43617245341775265585152 |
| 12 | 37385513306142843500105728 |
| 13 | 37862584188750782065354022912 |
[1,2,28,1112,87568,11447072,2239273408, 612359887232,223061763490048,104399900177326592, 61049165415292607488,43617245341775265585152, 37385513306142843500105728, 37862584188750782065354022912] |