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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 7 |
| 4 | 13 |
| 5 | 321 |
| 6 | 31 |
| 7 | 42673 |
| 8 | -214983 |
| 9 | 12251809 |
| 10 | -156239909 |
| 11 | 6366130761 |
| 12 | -135725103227 |
| 13 | 5265915854785 |
| 14 | -155145910919817 |
| 15 | 6318044844152161 |
| 16 | -232403136941014799 |
| 17 | 10299509100942804033 |
| 18 | -446889500139353805773 |
| 19 | 21789892230658085847673 |
| 20 | -1078684347590588362463619 |
[1,1,1,7,13,321,31,42673,-214983,12251809, -156239909,6366130761,-135725103227,5265915854785, -155145910919817,6318044844152161, -232403136941014799,10299509100942804033, -446889500139353805773,21789892230658085847673, -1078684347590588362463619] |