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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 64 |
| 3 | 993 |
| 4 | 13765 |
| 5 | 196699 |
| 6 | 2827609 |
| 7 | 40585250 |
| 8 | 582407760 |
| 9 | 8358259950 |
| 10 | 119952006315 |
| 11 | 1721463741562 |
| 12 | 24705187860146 |
| 13 | 354550820208077 |
| 14 | 5088254555610537 |
| 15 | 73022914681708450 |
| 16 | 1047971560792616433 |
[2,64,993,13765,196699,2827609,40585250,582407760, 8358259950,119952006315,1721463741562, 24705187860146,354550820208077,5088254555610537, 73022914681708450,1047971560792616433] |