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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 25 |
| 3 | 229 |
| 4 | 2315 |
| 5 | 32639 |
| 6 | 491900 |
| 7 | 10362539 |
| 8 | 228467758 |
| 9 | 5722056489 |
| 10 | 149001936472 |
| 11 | 4922785960065 |
| 12 | 167523724578682 |
| 13 | 5868253146213935 |
| 14 | 223161143280708212 |
| 15 | 8709152841093834203 |
| 16 | 400844191833597081550 |
| 17 | 19650074552687350830153 |
| 18 | 1002554646378888489419353 |
| 19 | 55160155625391554268894568 |
[4,25,229,2315,32639,491900,10362539,228467758, 5722056489,149001936472,4922785960065, 167523724578682,5868253146213935, 223161143280708212,8709152841093834203, 400844191833597081550,19650074552687350830153, 1002554646378888489419353, 55160155625391554268894568] |