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| n | a(n) |
|---|---|
| 1 | 81 |
| 2 | 437 |
| 3 | 2417 |
| 4 | 13893 |
| 5 | 81245 |
| 6 | 482409 |
| 7 | 2893685 |
| 8 | 17487137 |
| 9 | 106223237 |
| 10 | 647551889 |
| 11 | 3957272037 |
| 12 | 24224070993 |
| 13 | 148455289413 |
| 14 | 910505201009 |
| 15 | 5587258627429 |
| 16 | 34298159298769 |
| 17 | 210595144024709 |
| 18 | 1293294251436721 |
| 19 | 7943185773864101 |
[81,437,2417,13893,81245,482409,2893685,17487137, 106223237,647551889,3957272037,24224070993, 148455289413,910505201009,5587258627429, 34298159298769,210595144024709,1293294251436721, 7943185773864101] |