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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 2 |
| 4 | 40 |
| 5 | 32 |
| 6 | 464 |
| 7 | 272 |
| 8 | 7040 |
| 9 | 4864 |
| 10 | 136448 |
| 11 | 87808 |
| 12 | 3177472 |
| 13 | 2123776 |
| 14 | 86861824 |
| 15 | 57128960 |
| 16 | 2720112640 |
| 17 | 1806049280 |
| 18 | 96095928320 |
| 19 | 63587041280 |
| 20 | 3778819358720 |
| 21 | 2507078533120 |
| 22 | 163724570132480 |
| 23 | 108568842403840 |
| 24 | 7748467910901760 |
[1,2,6,2,40,32,464,272,7040,4864,136448,87808, 3177472,2123776,86861824,57128960,2720112640, 1806049280,96095928320,63587041280,3778819358720, 2507078533120,163724570132480,108568842403840, 7748467910901760] |