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| n | a(n) |
|---|---|
| 1 | 13 |
| 2 | 1215 |
| 3 | 76955 |
| 4 | 5280827 |
| 5 | 356768525 |
| 6 | 24177895648 |
| 7 | 1637496710797 |
| 8 | 110916199227139 |
| 9 | 7512747980759983 |
| 10 | 508867505795261823 |
| 11 | 34467532553765146717 |
| 12 | 2334617570886588879553 |
| 13 | 158132555108084876751600 |
[13,1215,76955,5280827,356768525,24177895648, 1637496710797,110916199227139,7512747980759983, 508867505795261823,34467532553765146717, 2334617570886588879553,158132555108084876751600] |