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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 2 |
| 2 | 2 |
| 3 | 6 |
| 4 | 4 |
| 5 | 20 |
| 6 | 6 |
| 7 | 42 |
| 8 | 8 |
| 9 | 864 |
| 10 | 20 |
| 11 | 42086 |
| 12 | 420 |
| 13 | 208 |
| 14 | 42 |
| 15 | 420 |
| 16 | 64 |
| 17 | 8642086 |
| 18 | 864 |
| 19 | 642086 |
| 20 | 20 |
| 21 | 42 |
| 22 | 42086 |
| 23 | 6420864 |
| 24 | 864 |
| 25 | -1 |
| 26 | 208 |
| 27 | 864 |
| 28 | 420 |
| 29 | 8642 |
| 30 | 420 |
| 31 | 86420864208642 |
| 32 | 64 |
| 33 | 420864208642086 |
| 34 | 8642086 |
| 35 | 420 |
| 36 | 864 |
| 37 | 86420864208642 |
| 38 | 642086 |
| 39 | 86420864208642086420864208642 |
| 40 | -1 |
| 41 | 642086420864208642 |
| 42 | 42 |
| 43 | 86 |
| 44 | 2086420864 |
| 45 | 6420864208642086420 |
| 46 | 6420864 |
| 47 | 2086420864208642086 |
| 48 | 864 |
| 49 | 208642 |
| 50 | -1 |
| 51 | 864208642086420864208642086420864 |
[0,2,2,6,4,20,6,42,8,864,20,42086,420,208,42,420, 64,8642086,864,642086,20,42,42086,6420864,864,-1, 208,864,420,8642,420,86420864208642,64, 420864208642086,8642086,420,864,86420864208642, 642086,86420864208642086420864208642,-1, 642086420864208642,42,86,2086420864, 6420864208642086420,6420864,2086420864208642086, 864,208642,-1,864208642086420864208642086420864] |