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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 27 |
| 4 | 109 |
| 5 | 462 |
| 6 | 2021 |
| 7 | 8957 |
| 8 | 40478 |
| 9 | 184607 |
| 10 | 850670 |
| 11 | 3949965 |
| 12 | 18446391 |
| 13 | 86653625 |
| 14 | 408802335 |
| 15 | 1936326814 |
| 16 | 9203631648 |
| 17 | 43874127953 |
| 18 | 209728998818 |
| 19 | 1004912328372 |
| 20 | 4825390938764 |
| 21 | 23215849225298 |
| 22 | 111890312560604 |
| 23 | 540135699843988 |
| 24 | 2611244410884437 |
| 25 | 12640886843737626 |
| 26 | 61270116153307678 |
[1,2,7,27,109,462,2021,8957,40478,184607,850670, 3949965,18446391,86653625,408802335,1936326814, 9203631648,43874127953,209728998818,1004912328372, 4825390938764,23215849225298,111890312560604, 540135699843988,2611244410884437, 12640886843737626,61270116153307678] |