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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 13 |
| 4 | 61 |
| 5 | 201 |
| 6 | 961 |
| 7 | 3485 |
| 8 | 16953 |
| 9 | 65057 |
| 10 | 318501 |
| 11 | 1270385 |
| 12 | 6239385 |
| 13 | 25567503 |
| 14 | 125918427 |
| 15 | 526336207 |
| 16 | 2597780455 |
| 17 | 11027051415 |
| 18 | 54512432667 |
| 19 | 234248644823 |
| 20 | 1159487821623 |
| 21 | 5032467482813 |
| 22 | 24935946686145 |
| 23 | 109128642457511 |
| 24 | 541205201186051 |
| 25 | 2385127987378705 |
| 26 | 11837318239533357 |
| 27 | 52480754874395537 |
[1,1,5,13,61,201,961,3485,16953,65057,318501, 1270385,6239385,25567503,125918427,526336207, 2597780455,11027051415,54512432667,234248644823, 1159487821623,5032467482813,24935946686145, 109128642457511,541205201186051,2385127987378705, 11837318239533357,52480754874395537] |