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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 63 |
| 5 | 326 |
| 6 | 1769 |
| 7 | 9964 |
| 8 | 57843 |
| 9 | 344203 |
| 10 | 2090470 |
| 11 | 12912988 |
| 12 | 80899801 |
| 13 | 512896540 |
| 14 | 3284651548 |
| 15 | 21217493460 |
| 16 | 138080484819 |
| 17 | 904454380446 |
| 18 | 5958186674879 |
| 19 | 39448465279220 |
| 20 | 262359379484522 |
| 21 | 1751912981641794 |
| 22 | 11741044418866476 |
[1,3,13,63,326,1769,9964,57843,344203,2090470, 12912988,80899801,512896540,3284651548, 21217493460,138080484819,904454380446, 5958186674879,39448465279220,262359379484522, 1751912981641794,11741044418866476] |