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| n | a(n) |
|---|---|
| 2 | 4 |
| 3 | 10 |
| 4 | 58 |
| 5 | 58 |
| 6 | 418 |
| 7 | 838 |
| 8 | 2518 |
| 9 | 2518 |
| 10 | 27718 |
| 11 | 27718 |
| 12 | 360358 |
| 13 | 360358 |
| 14 | 360358 |
| 15 | 720718 |
| 16 | 12252238 |
| 17 | 12252238 |
| 18 | 232792558 |
| 19 | 232792558 |
| 20 | 232792558 |
| 21 | 232792558 |
| 22 | 5354228878 |
| 23 | 5354228878 |
| 24 | 26771144398 |
| 25 | 26771144398 |
| 26 | 80313433198 |
| 27 | 80313433198 |
| 28 | 2329089562798 |
[4,10,58,58,418,838,2518,2518,27718,27718,360358, 360358,360358,720718,12252238,12252238,232792558, 232792558,232792558,232792558,5354228878, 5354228878,26771144398,26771144398,80313433198, 80313433198,2329089562798] |