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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 6 |
| 4 | 17 |
| 5 | 20 |
| 6 | 97 |
| 7 | 1498 |
| 8 | 7009 |
| 9 | -8952 |
| 10 | -44991 |
| 11 | 2641870 |
| 12 | 16678257 |
| 13 | -147810468 |
| 14 | -1072851167 |
| 15 | 22562632802 |
| 16 | 182236444097 |
| 17 | -3111217127536 |
| 18 | -28067216775039 |
| 19 | 608465230881302 |
| 20 | 6014702853818321 |
| 21 | -136728540813908444 |
[1,0,1,6,17,20,97,1498,7009,-8952,-44991,2641870, 16678257,-147810468,-1072851167,22562632802, 182236444097,-3111217127536,-28067216775039, 608465230881302,6014702853818321, -136728540813908444] |