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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 7 |
| 4 | 49 |
| 5 | 541 |
| 6 | 7321 |
| 7 | 122011 |
| 8 | 2390977 |
| 9 | 54027289 |
| 10 | 1382140081 |
| 11 | 39493358191 |
| 12 | 1246693438321 |
| 13 | 43087256236597 |
| 14 | 1618203187947529 |
| 15 | 65621724413560771 |
| 16 | 2857736621103221761 |
| 17 | 133014764141210620081 |
| 18 | 6589916027200886776417 |
[1,1,1,7,49,541,7321,122011,2390977,54027289, 1382140081,39493358191,1246693438321, 43087256236597,1618203187947529,65621724413560771, 2857736621103221761,133014764141210620081, 6589916027200886776417] |