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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 12 |
| 4 | 65 |
| 5 | 464 |
| 6 | 4235 |
| 7 | 48000 |
| 8 | 658197 |
| 9 | 10676571 |
| 10 | 200994145 |
| 11 | 4321369524 |
| 12 | 104676808756 |
| 13 | 2824120458186 |
| 14 | 84038944594677 |
| 15 | 2735391623889696 |
| 16 | 96690702098948611 |
| 17 | 3688764754855986702 |
| 18 | 151064345601782722492 |
| 19 | 6609564176073032406148 |
| 20 | 307682727619722793499662 |
[1,3,12,65,464,4235,48000,658197,10676571, 200994145,4321369524,104676808756,2824120458186, 84038944594677,2735391623889696,96690702098948611, 3688764754855986702,151064345601782722492, 6609564176073032406148,307682727619722793499662] |