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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 15 |
| 4 | 111 |
| 5 | 1119 |
| 6 | 14583 |
| 7 | 236775 |
| 8 | 4659951 |
| 9 | 108835599 |
| 10 | 2965927143 |
| 11 | 93015145335 |
| 12 | 3318634499871 |
| 13 | 133400225472159 |
| 14 | 5991382911276183 |
| 15 | 298493219945303175 |
| 16 | 16392036941979061071 |
| 17 | 986729309825162666799 |
| 18 | 64784791274694379877703 |
| 19 | 4618773443181937984415895 |
[1,1,3,15,111,1119,14583,236775,4659951,108835599, 2965927143,93015145335,3318634499871, 133400225472159,5991382911276183, 298493219945303175,16392036941979061071, 986729309825162666799,64784791274694379877703, 4618773443181937984415895] |