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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 10 |
| 4 | 42 |
| 5 | 589 |
| 6 | 2186 |
| 7 | 30253 |
| 8 | 113307 |
| 9 | 1608668 |
| 10 | 88157689 |
| 11 | 336717854 |
| 12 | 19015826478 |
| 13 | 282528883551 |
| 14 | 1091574618496 |
| 15 | 16360940729894 |
[1,2,10,42,589,2186,30253,113307,1608668,88157689, 336717854,19015826478,282528883551,1091574618496, 16360940729894] |