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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 7 |
| 4 | 17 |
| 5 | 121 |
| 6 | 353 |
| 7 | 2591 |
| 8 | 8257 |
| 9 | 61921 |
| 10 | 207905 |
| 11 | 1582791 |
| 12 | 5501073 |
| 13 | 42344121 |
| 14 | 150827073 |
| 15 | 1170747519 |
| 16 | 4247388417 |
| 17 | 33186295681 |
| 18 | 122125206977 |
| 19 | 959260792775 |
| 20 | 3570473750929 |
| 21 | 28167068630713 |
| 22 | 105820555054241 |
| 23 | 837838806587167 |
| 24 | 3172136074486337 |
[1,1,7,17,121,353,2591,8257,61921,207905,1582791, 5501073,42344121,150827073,1170747519,4247388417, 33186295681,122125206977,959260792775, 3570473750929,28167068630713,105820555054241, 837838806587167,3172136074486337] |