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| n | a(n) |
|---|---|
| 0 | 13 |
| 1 | 27 |
| 2 | 715 |
| 3 | 1457 |
| 4 | 38597 |
| 5 | 78651 |
| 6 | 2083523 |
| 7 | 4245697 |
| 8 | 112471645 |
| 9 | 229188987 |
| 10 | 6071385307 |
| 11 | 12371959601 |
| 12 | 327742334933 |
| 13 | 667856629467 |
| 14 | 17692014701075 |
| 15 | 36051886031617 |
| 16 | 955041051523117 |
| 17 | 1946133989077851 |
| 18 | 51554524767547243 |
| 19 | 105055183524172337 |
| 20 | 2782989296396028005 |
[13,27,715,1457,38597,78651,2083523,4245697, 112471645,229188987,6071385307,12371959601, 327742334933,667856629467,17692014701075, 36051886031617,955041051523117,1946133989077851, 51554524767547243,105055183524172337, 2782989296396028005] |