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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 19 |
| 3 | 632 |
| 4 | 19245637 |
| 5 | 5158701627878530987 |
| 6 | 101362012359740449534162019620212891642247346 |
[4,19,632,19245637,5158701627878530987, 101362012359740449534162019620212891642247346] |