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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 15 |
| 4 | 71 |
| 5 | 239 |
| 6 | 1163 |
| 7 | 4345 |
| 8 | 21417 |
| 9 | 83977 |
| 10 | 416265 |
| 11 | 1686337 |
| 12 | 8383997 |
| 13 | 34790589 |
| 14 | 173269929 |
| 15 | 731926875 |
| 16 | 3649321671 |
| 17 | 15627492163 |
| 18 | 77977391863 |
| 19 | 337568268171 |
| 20 | 1685309454471 |
| 21 | 7360687552519 |
| 22 | 36762621786387 |
| 23 | 161749719323503 |
| 24 | 808077816764431 |
| 25 | 3577616979975647 |
| 26 | 17876871296933983 |
| 27 | 79569969818904111 |
[1,1,5,15,71,239,1163,4345,21417,83977,416265, 1686337,8383997,34790589,173269929,731926875, 3649321671,15627492163,77977391863,337568268171, 1685309454471,7360687552519,36762621786387, 161749719323503,808077816764431,3577616979975647, 17876871296933983,79569969818904111] |