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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 102 |
| 5 | 2730 |
| 6 | 73965 |
| 7 | 1747893 |
| 8 | 39747932 |
| 9 | 941571576 |
| 10 | 21552984495 |
| 11 | 440593787755 |
| 12 | 8246912787894 |
| 13 | 145396398912414 |
| 14 | 2456171567279885 |
| 15 | 40123597587869565 |
| 16 | 636426718791995640 |
| 17 | 9804070912688974376 |
| 18 | 146378210616014587821 |
[1,3,102,2730,73965,1747893,39747932,941571576, 21552984495,440593787755,8246912787894, 145396398912414,2456171567279885, 40123597587869565,636426718791995640, 9804070912688974376,146378210616014587821] |