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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 7 |
| 3 | 52 |
| 4 | 442 |
| 5 | 4345 |
| 6 | 49114 |
| 7 | 632104 |
| 8 | 9167575 |
| 9 | 148388893 |
| 10 | 2657338636 |
| 11 | 52244218837 |
| 12 | 1120000171417 |
| 13 | 26024217218746 |
| 14 | 651943279016898 |
| 15 | 17525338687574976 |
| 16 | 503409841260165202 |
| 17 | 15393623230236299133 |
[1,1,7,52,442,4345,49114,632104,9167575,148388893, 2657338636,52244218837,1120000171417, 26024217218746,651943279016898,17525338687574976, 503409841260165202,15393623230236299133] |