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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 7 |
| 3 | 47 |
| 4 | 521 |
| 5 | 7233 |
| 6 | 129443 |
| 7 | 2811701 |
| 8 | 73203561 |
| 9 | 2229207953 |
| 10 | 78389689559 |
| 11 | 3138945552419 |
| 12 | 141714151130833 |
| 13 | 7146006410498833 |
| 14 | 399443567886826899 |
| 15 | 24581290495461129817 |
| 16 | 1655664011866577666737 |
| 17 | 121413069330848040859809 |
| 18 | 9648772995329567310573319 |
[1,1,7,47,521,7233,129443,2811701,73203561, 2229207953,78389689559,3138945552419, 141714151130833,7146006410498833, 399443567886826899,24581290495461129817, 1655664011866577666737,121413069330848040859809, 9648772995329567310573319] |