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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 3 |
| 3 | -1 |
| 4 | 41 |
| 5 | 299 |
| 6 | 4531 |
| 7 | 74507 |
| 8 | 1474481 |
| 9 | 33540119 |
| 10 | 864507491 |
| 11 | 24891022199 |
| 12 | 791755864153 |
| 13 | 27571976573699 |
| 14 | 1043247441846611 |
| 15 | 42615848603499779 |
| 16 | 1869129393654945761 |
| 17 | 87605345727468933167 |
| 18 | 4369604246576366377411 |
| 19 | 231091472431638655755119 |
[1,-1,3,-1,41,299,4531,74507,1474481,33540119, 864507491,24891022199,791755864153,27571976573699, 1043247441846611,42615848603499779, 1869129393654945761,87605345727468933167, 4369604246576366377411,231091472431638655755119] |