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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 15 |
| 2 | 285 |
| 3 | 8475 |
| 4 | 378105 |
| 5 | 23823015 |
| 6 | 2018820885 |
| 7 | 221605991475 |
| 8 | 30596648805105 |
| 9 | 5189967817758015 |
| 10 | 1061021392126671885 |
| 11 | 257296819626005894475 |
| 12 | 73023341368629447792105 |
| 13 | 23978466652359211809453015 |
[1,15,285,8475,378105,23823015,2018820885, 221605991475,30596648805105,5189967817758015, 1061021392126671885,257296819626005894475, 73023341368629447792105, 23978466652359211809453015] |