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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 12 |
| 3 | 321 |
| 4 | 15280 |
| 5 | 1127745 |
| 6 | 118507536 |
| 7 | 16731979033 |
| 8 | 3044595017472 |
| 9 | 692050790547297 |
| 10 | 191796657547052800 |
| 11 | 63563842088104098081 |
| 12 | 24793529117087476242432 |
| 13 | 11232023076988690608825505 |
| 14 | 5843573099019743656060348416 |
| 15 | 3457799186387568447755745563625 |
[1,1,12,321,15280,1127745,118507536,16731979033, 3044595017472,692050790547297,191796657547052800, 63563842088104098081,24793529117087476242432, 11232023076988690608825505, 5843573099019743656060348416, 3457799186387568447755745563625] |