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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | -3 |
| 3 | 19 |
| 4 | -105 |
| 5 | 690 |
| 6 | -4781 |
| 7 | 34708 |
| 8 | -260189 |
| 9 | 1999169 |
| 10 | -15660175 |
| 11 | 124596499 |
| 12 | -1004110947 |
| 13 | 8179379808 |
| 14 | -67239070867 |
| 15 | 557098881920 |
| 16 | -4647368670949 |
| 17 | 39001655222788 |
| 18 | -329048378867467 |
| 19 | 2789241880512899 |
| 20 | -23743798316713367 |
| 21 | 202894843070927860 |
[1,2,-3,19,-105,690,-4781,34708,-260189,1999169, -15660175,124596499,-1004110947,8179379808, -67239070867,557098881920,-4647368670949, 39001655222788,-329048378867467,2789241880512899, -23743798316713367,202894843070927860] |