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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 15 |
| 4 | 113 |
| 5 | 1105 |
| 6 | 13219 |
| 7 | 187103 |
| 8 | 3058113 |
| 9 | 56675297 |
| 10 | 1174295267 |
| 11 | 26898243439 |
| 12 | 674916701169 |
| 13 | 18409502066097 |
| 14 | 542373965958595 |
| 15 | 17164148092886207 |
| 16 | 580677914417571585 |
| 17 | 20913258579319759041 |
| 18 | 798876414332323236931 |
| 19 | 32261582928825038942671 |
| 20 | 1373304514339211081661169 |
[1,1,3,15,113,1105,13219,187103,3058113,56675297, 1174295267,26898243439,674916701169, 18409502066097,542373965958595,17164148092886207, 580677914417571585,20913258579319759041, 798876414332323236931,32261582928825038942671, 1373304514339211081661169] |