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| n | a(n) |
|---|---|
| 1 | 6 |
| 2 | 36 |
| 3 | 432 |
| 4 | 1728 |
| 5 | 27000 |
| 6 | 139968 |
| 7 | 1778112 |
| 8 | 6635520 |
| 9 | 113467392 |
| 10 | 534600000 |
| 11 | 6963536448 |
| 12 | 26121388032 |
| 13 | 465193834560 |
| 14 | 2427720325632 |
| 15 | 28548223200000 |
| 16 | 109586090557440 |
| 17 | 1910296842179040 |
| 18 | 9618417501143040 |
| 19 | 123523151337020736 |
| 20 | 406467072000000000 |
| 21 | 7713001620195508224 |
[6,36,432,1728,27000,139968,1778112,6635520, 113467392,534600000,6963536448,26121388032, 465193834560,2427720325632,28548223200000, 109586090557440,1910296842179040,9618417501143040, 123523151337020736,406467072000000000, 7713001620195508224] |