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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 13 |
| 3 | 139 |
| 4 | 1787 |
| 5 | 11913 |
| 6 | 102895 |
| 7 | 883493 |
| 8 | 7534239 |
| 9 | 62963491 |
| 10 | 533335257 |
| 11 | 4512230169 |
| 12 | 38134861983 |
| 13 | 322180217835 |
| 14 | 2723529411351 |
| 15 | 23020233823025 |
| 16 | 194563962109999 |
| 17 | 1644444704071007 |
| 18 | 13899067616530479 |
| 19 | 117475708664617727 |
[1,13,139,1787,11913,102895,883493,7534239, 62963491,533335257,4512230169,38134861983, 322180217835,2723529411351,23020233823025, 194563962109999,1644444704071007, 13899067616530479,117475708664617727] |