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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 40 |
| 4 | 462 |
| 5 | 7907 |
| 6 | 206846 |
| 7 | 6670844 |
| 8 | 277121424 |
| 9 | 14390352620 |
| 10 | 947692403880 |
| 11 | 72583382625408 |
| 12 | 6575489103737088 |
| 13 | 696011636400194304 |
| 14 | 86805454700886653952 |
| 15 | 12166531324546826156544 |
| 16 | 1933901484265841951655936 |
[1,6,40,462,7907,206846,6670844,277121424, 14390352620,947692403880,72583382625408, 6575489103737088,696011636400194304, 86805454700886653952,12166531324546826156544, 1933901484265841951655936] |