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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | -1 |
| 5 | 5 |
| 6 | -1 |
| 7 | 19 |
| 8 | -1 |
| 9 | 81 |
| 10 | -1 |
| 11 | -1 |
| 12 | -1 |
| 13 | 90 |
| 14 | 1885 |
| 15 | 4799 |
| 16 | -1 |
| 17 | 21905 |
| 18 | -1 |
| 19 | 69492 |
| 20 | -1 |
| 21 | 99206 |
| 22 | -1 |
| 23 | -1 |
| 24 | -1 |
| 25 | 585398 |
| 26 | 8985436 |
| 27 | 32569980 |
| 28 | -1 |
| 29 | -1 |
| 30 | -1 |
| 31 | 634005911 |
| 32 | -1 |
| 33 | -1 |
| 34 | -1 |
| 35 | -1 |
| 36 | -1 |
| 37 | 7348910325 |
| 38 | 40154162248 |
| 39 | 28169995830 |
| 40 | -1 |
| 41 | -1 |
| 42 | -1 |
| 43 | -1 |
| 44 | -1 |
| 45 | 749259285289 |
| 46 | -1 |
| 47 | -1 |
| 48 | -1 |
| 49 | 22640169503650 |
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