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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 9 |
| 8 | 15 |
| 9 | 53 |
| 10 | 69 |
| 11 | 367 |
| 12 | 797 |
| 13 | 5383 |
| 14 | 14177 |
| 15 | 132187 |
| 16 | 419443 |
| 17 | 4770865 |
| 18 | 18981007 |
| 19 | 272701021 |
| 20 | 1381813173 |
| 21 | 25671154071 |
| 22 | 163453499965 |
[1,1,1,1,1,1,9,15,53,69,367,797,5383,14177,132187, 419443,4770865,18981007,272701021,1381813173, 25671154071,163453499965] |