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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 378 |
| 4 | 4284 |
| 5 | 294525 |
| 6 | 3180870 |
| 7 | 59376240 |
| 8 | 2510766720 |
| 9 | 2824612560 |
| 10 | 147507544800 |
| 11 | 2109357890640 |
| 12 | 43721236278720 |
| 13 | 1468304851693680 |
| 14 | 105943842376051680 |
| 15 | 113511259688626800 |
| 16 | 121078677001201920 |
| 17 | 5274489866864858640 |
| 18 | 161957865323732718240 |
| 19 | 3931977063692844326160 |
[1,7,378,4284,294525,3180870,59376240,2510766720, 2824612560,147507544800,2109357890640, 43721236278720,1468304851693680, 105943842376051680,113511259688626800, 121078677001201920,5274489866864858640, 161957865323732718240,3931977063692844326160] |