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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 2 |
| 2 | 2 |
| 3 | 6 |
| 4 | 4 |
| 5 | -1 |
| 6 | 6 |
| 7 | 686 |
| 8 | 8 |
| 9 | 666 |
| 10 | 2 |
| 11 | 22 |
| 12 | 444 |
| 13 | 2002 |
| 14 | 686 |
| 15 | -1 |
| 16 | 464 |
| 17 | 646 |
| 18 | 666 |
| 19 | 646 |
| 20 | 2 |
| 21 | 6006 |
| 22 | 22 |
| 23 | 828 |
| 24 | 888 |
| 25 | -1 |
| 26 | 2002 |
| 27 | 8886888 |
| 28 | 868 |
| 29 | 464 |
| 30 | 6 |
| 31 | 868 |
| 32 | 4224 |
| 33 | 66 |
| 34 | 646 |
| 35 | -1 |
| 36 | 828 |
| 37 | 222 |
| 38 | 646 |
| 39 | 6006 |
| 40 | 4 |
| 41 | 22222 |
| 42 | 6006 |
| 43 | 68886 |
| 44 | 44 |
| 45 | -1 |
| 46 | 828 |
| 47 | 282 |
| 48 | 4224 |
| 49 | 686 |
| 50 | -1 |
| 51 | 42024 |
| 52 | 4004 |
| 53 | 424 |
| 54 | 8886888 |
| 55 | -1 |
| 56 | 8008 |
| 57 | 68286 |
| 58 | 464 |
| 59 | 68086 |
| 60 | 6 |
[0,2,2,6,4,-1,6,686,8,666,2,22,444,2002,686,-1, 464,646,666,646,2,6006,22,828,888,-1,2002,8886888, 868,464,6,868,4224,66,646,-1,828,222,646,6006,4, 22222,6006,68886,44,-1,828,282,4224,686,-1,42024, 4004,424,8886888,-1,8008,68286,464,68086,6] |