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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 58 |
| 5 | 632 |
| 6 | 9654 |
| 7 | 202484 |
| 8 | 5843954 |
| 9 | 233064944 |
| 10 | 12916716526 |
| 11 | 998745087980 |
| 12 | 108135391731690 |
| 13 | 16434082400952296 |
| 14 | 3513344943520006118 |
| 15 | 1058030578581541945316 |
| 16 | 449389062270642095128546 |
| 17 | 269419653009366144571801568 |
| 18 | 228157953744571034350576205790 |
[1,2,8,58,632,9654,202484,5843954,233064944, 12916716526,998745087980,108135391731690, 16434082400952296,3513344943520006118, 1058030578581541945316,449389062270642095128546, 269419653009366144571801568, 228157953744571034350576205790] |