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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 5 |
| 3 | 15 |
| 4 | 59 |
| 5 | 257 |
| 6 | 1205 |
| 7 | 5879 |
| 8 | 29693 |
| 9 | 153097 |
| 10 | 806375 |
| 11 | 4307317 |
| 12 | 23313947 |
| 13 | 127420533 |
| 14 | 702562447 |
| 15 | 3900415155 |
| 16 | 21786817517 |
| 17 | 122309555899 |
| 18 | 689707853981 |
| 19 | 3904123962093 |
| 20 | 22174631940293 |
| 21 | 126322762595339 |
| 22 | 721552901977497 |
[2,5,15,59,257,1205,5879,29693,153097,806375, 4307317,23313947,127420533,702562447,3900415155, 21786817517,122309555899,689707853981, 3904123962093,22174631940293,126322762595339, 721552901977497] |