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| n | a(n) |
|---|---|
| 1 | 7 |
| 2 | 18 |
| 3 | 220 |
| 4 | 2623 |
| 5 | 22970 |
| 6 | 185295 |
| 7 | 1455308 |
| 8 | 11001188 |
| 9 | 78655701 |
| 10 | 530818425 |
| 11 | 3400770086 |
| 12 | 20765160878 |
| 13 | 121095265926 |
| 14 | 675886798131 |
| 15 | 3619746974319 |
| 16 | 18647969101899 |
| 17 | 92619652248187 |
| 18 | 444385154988709 |
| 19 | 2063495070975608 |
[7,18,220,2623,22970,185295,1455308,11001188, 78655701,530818425,3400770086,20765160878, 121095265926,675886798131,3619746974319, 18647969101899,92619652248187,444385154988709, 2063495070975608] |