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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 9 |
| 4 | 109 |
| 5 | 1569 |
| 6 | 25481 |
| 7 | 454105 |
| 8 | 8730373 |
| 9 | 178996865 |
| 10 | 3881556561 |
| 11 | 88477557289 |
| 12 | 2109927671453 |
| 13 | 52443846331297 |
| 14 | 1354646602217945 |
| 15 | 36275862587452281 |
| 16 | 1005099719255707829 |
| 17 | 28765965099599741953 |
| 18 | 849204340574458575777 |
| 19 | 25827102287376124267593 |
| 20 | 808349897942417046805197 |
| 21 | 26011340193853765710238241 |
| 22 | 859773626049480606121078057 |
| 23 | 29168437337569276216572259097 |
[1,1,9,109,1569,25481,454105,8730373,178996865, 3881556561,88477557289,2109927671453, 52443846331297,1354646602217945,36275862587452281, 1005099719255707829,28765965099599741953, 849204340574458575777,25827102287376124267593, 808349897942417046805197, 26011340193853765710238241, 859773626049480606121078057, 29168437337569276216572259097] |