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| n | a(n) |
|---|---|
| 1 | 155 |
| 2 | 439 |
| 3 | 1603 |
| 4 | 5449 |
| 5 | 18681 |
| 6 | 64891 |
| 7 | 222813 |
| 8 | 764865 |
| 9 | 2637815 |
| 10 | 9090487 |
| 11 | 31281933 |
| 12 | 107674395 |
| 13 | 370788133 |
| 14 | 1276814309 |
| 15 | 4396089911 |
| 16 | 15135449051 |
| 17 | 52112945503 |
| 18 | 179433951141 |
| 19 | 617811988681 |
| 20 | 2127175449173 |
| 21 | 7324071255063 |
| 22 | 25217614284475 |
[155,439,1603,5449,18681,64891,222813,764865, 2637815,9090487,31281933,107674395,370788133, 1276814309,4396089911,15135449051,52112945503, 179433951141,617811988681,2127175449173, 7324071255063,25217614284475] |