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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 25 |
| 4 | 210 |
| 5 | 10243 |
| 6 | 262443 |
| 7 | 22032028 |
| 8 | 4876165115 |
| 9 | 1298903907523 |
| 10 | 871790327970014 |
[1,7,25,210,10243,262443,22032028,4876165115, 1298903907523,871790327970014] |