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| n | a(n) |
|---|---|
| 3 | 1 |
| 4 | 2 |
| 5 | 6 |
| 6 | 23 |
| 7 | 109 |
| 8 | 618 |
| 9 | 4096 |
| 10 | 31133 |
| 11 | 267219 |
| 12 | 2557502 |
| 13 | 27011734 |
| 14 | 312115953 |
| 15 | 3916844779 |
| 16 | 53053052462 |
| 17 | 771450742596 |
| 18 | 11986779006647 |
| 19 | 198204672604489 |
| 20 | 3475110017769282 |
| 21 | 64396888392712366 |
| 22 | 1257612452945760503 |
| 23 | 25815617698822423341 |
| 24 | 555708180579477963962 |
| 25 | 12517189538209383465496 |
[1,2,6,23,109,618,4096,31133,267219,2557502, 27011734,312115953,3916844779,53053052462, 771450742596,11986779006647,198204672604489, 3475110017769282,64396888392712366, 1257612452945760503,25815617698822423341, 555708180579477963962,12517189538209383465496] |