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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 5 |
| 3 | 17 |
| 4 | 57 |
| 5 | 185 |
| 6 | 593 |
| 7 | 1901 |
| 8 | 6121 |
| 9 | 19793 |
| 10 | 64161 |
| 11 | 208085 |
| 12 | 674105 |
| 13 | 2179001 |
| 14 | 7023409 |
| 15 | 22566269 |
| 16 | 72268809 |
| 17 | 230696609 |
| 18 | 734153537 |
| 19 | 2329503653 |
| 20 | 7371475033 |
| 21 | 23267249417 |
| 22 | 73268609745 |
| 23 | 230224239437 |
| 24 | 721965697577 |
| 25 | 2259855722225 |
[2,5,17,57,185,593,1901,6121,19793,64161,208085, 674105,2179001,7023409,22566269,72268809, 230696609,734153537,2329503653,7371475033, 23267249417,73268609745,230224239437,721965697577, 2259855722225] |