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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 25 |
| 3 | 537 |
| 4 | 661 |
| 5 | 5199 |
| 6 | 113253 |
| 7 | 240621 |
| 8 | 5337048977 |
| 9 | 17434578479 |
| 10 | 34216676921 |
| 11 | 1991831965911 |
| 12 | 4495321247369 |
| 13 | 22567781434431 |
| 14 | 37328883555791 |
| 15 | 110447613624133 |
| 16 | 188368390470877 |
| 17 | 324587968952249 |
| 18 | 1983705516917661 |
[1,25,537,661,5199,113253,240621,5337048977, 17434578479,34216676921,1991831965911, 4495321247369,22567781434431,37328883555791, 110447613624133,188368390470877,324587968952249, 1983705516917661] |