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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 10 |
| 4 | 84 |
| 5 | 988 |
| 6 | 14944 |
| 7 | 276288 |
| 8 | 6037088 |
| 9 | 152213344 |
| 10 | 4349539776 |
| 11 | 138913306816 |
| 12 | 4903586835328 |
| 13 | 189581185491072 |
| 14 | 7966928227397120 |
| 15 | 361586320101395968 |
| 16 | 17626603314884699136 |
| 17 | 918522989907500809216 |
| 18 | 50952388648850059964416 |
| 19 | 2997739520942089756839936 |
[1,2,10,84,988,14944,276288,6037088,152213344, 4349539776,138913306816,4903586835328, 189581185491072,7966928227397120, 361586320101395968,17626603314884699136, 918522989907500809216,50952388648850059964416, 2997739520942089756839936] |