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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 17 |
| 8 | 21 |
| 9 | 549 |
| 10 | 1079 |
| 11 | 10673 |
| 12 | 26871 |
| 13 | 476485 |
| 14 | 1364599 |
| 15 | 88490477 |
| 16 | 316329117 |
| 17 | 38154154091 |
| 18 | 169142706059 |
| 19 | 28100677201207 |
| 20 | 150981261883543 |
| 21 | 38976852011544623 |
[1,1,1,1,1,1,17,21,549,1079,10673,26871,476485, 1364599,88490477,316329117,38154154091, 169142706059,28100677201207,150981261883543, 38976852011544623] |