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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -3 |
| 2 | 21 |
| 3 | -27 |
| 4 | 189 |
| 5 | -243 |
| 6 | 1701 |
| 7 | -2187 |
| 8 | 15309 |
| 9 | -19683 |
| 10 | 137781 |
| 11 | -177147 |
| 12 | 1240029 |
| 13 | -1594323 |
| 14 | 11160261 |
| 15 | -14348907 |
| 16 | 100442349 |
| 17 | -129140163 |
| 18 | 903981141 |
| 19 | -1162261467 |
| 20 | 8135830269 |
| 21 | -10460353203 |
| 22 | 73222472421 |
| 23 | -94143178827 |
| 24 | 659002251789 |
| 25 | -847288609443 |
[1,-3,21,-27,189,-243,1701,-2187,15309,-19683, 137781,-177147,1240029,-1594323,11160261, -14348907,100442349,-129140163,903981141, -1162261467,8135830269,-10460353203,73222472421, -94143178827,659002251789,-847288609443] |