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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 34 |
| 4 | 481 |
| 5 | 8731 |
| 6 | 174454 |
| 7 | 3603244 |
| 8 | 75251971 |
| 9 | 1577395861 |
| 10 | 33105096904 |
| 11 | 695065679254 |
| 12 | 14595390246661 |
| 13 | 306496273473391 |
| 14 | 6436373295247354 |
| 15 | 135163500079092064 |
| 16 | 2838431127851480551 |
| 17 | 59607037068329713321 |
[1,4,34,481,8731,174454,3603244,75251971, 1577395861,33105096904,695065679254, 14595390246661,306496273473391,6436373295247354, 135163500079092064,2838431127851480551, 59607037068329713321] |