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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 33 |
| 4 | 101 |
| 5 | 277 |
| 6 | 709 |
| 7 | 1733 |
| 8 | 4101 |
| 9 | 9477 |
| 10 | 21509 |
| 11 | 48133 |
| 12 | 106501 |
| 13 | 233477 |
| 14 | 507909 |
| 15 | 1097733 |
| 16 | 2359301 |
| 17 | 5046277 |
| 18 | 10747909 |
| 19 | 22806533 |
| 20 | 48234501 |
| 21 | 101711877 |
| 22 | 213909509 |
| 23 | 448790533 |
| 24 | 939524101 |
| 25 | 1962934277 |
| 26 | 4093640709 |
| 27 | 8522825733 |
[1,2,9,33,101,277,709,1733,4101,9477,21509,48133, 106501,233477,507909,1097733,2359301,5046277, 10747909,22806533,48234501,101711877,213909509, 448790533,939524101,1962934277,4093640709, 8522825733] |