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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 21 |
| 7 | 47 |
| 8 | 269 |
| 9 | 1463 |
| 10 | 8149 |
| 11 | 63091 |
| 12 | 761263 |
| 13 | 8894963 |
| 14 | 159626291 |
| 15 | 3010312887 |
| 16 | 80637272407 |
[1,1,1,1,1,21,47,269,1463,8149,63091,761263, 8894963,159626291,3010312887,80637272407] |